The Gotthard Pass or St. Gotthard Pass at 2,106 m is a mountain pass in the Alps traversing the Saint-Gotthard Massif and connecting northern and southern Switzerland; the pass lies between Airolo in the Italian-speaking canton of Ticino, Andermatt in the German-speaking canton of Uri, connects further Bellinzona to Lucerne and Zurich. The Gotthard Pass lies at the hearth of the Gotthard, an important north-south axis in Europe, is it crossed by three major traffic tunnels, each being the world's longest at the time of their construction: the Gotthard Rail Tunnel, the Gotthard Road Tunnel and the Gotthard Base Tunnel. With the Lötschberg to the west, the Gotthard is one of the two main north-south routes through the Swiss Alps. Since the Middle Ages, transit across the Gotthard played an important role in Swiss history, the region north of Gotthard becoming the nucleus of the Swiss Confederacy in the early 14th century; the Gotthard Pass lies on the main watershed of the Gotthard massif, a massif lying at the heart of the Swiss Alps, between the cantons of Valais, Ticino and Uri.
The pass itself is the lowest point between the summits of Pizzo Centrale. It connects the cantons of Uri and Ticino, its summit being located in the latter canton, about 2 km south of the border with Uri; the valleys connected by the pass are that of the river Reuss, named the Urseren, that of the river Ticino, named Valle Leventina. The Gotthard axis is the most important route between Central Switzerland as well as most of the northern part of the country and the southern region of Ticino, it is the most direct link between Zürich and Lugano and between some regions of northern Europe and Italy. The nearest towns are Hospental near Andermatt and Airolo in the valleys of Urseren and Leventina; the region of Andermatt lies at the foot of the Furka and Oberalp Passes connecting the Rhone and Rhine Valleys thus making the Gotthard area a strategic place for transports and military. Just southeast of the culminating point of the Gotthard Pass, at an elevation of about 2,090 metres above sea level, are several lakes.
The largest has a surface of 3.94 hectares. South of Lago della Piazza are National Museum, as well as a hotel and restaurants. Another official road sign displaying an elevation of 2,091 metres lies there. A few kilometres away and above the Gotthard Pass are found two large dams and artificial lakes: Lago di Lucendro at the foot of Pizzo Lucendro and Lago della Sella at the foot of Pizzo Centrale, they are part of the Reuss and Ticino basin, although both are located within the canton of Ticino. Though the pass was locally known in antiquity, it was not used until the early 13th century because travel involved fording the turbulent Reuss, swollen with snowmelt during the early summer, in the narrow steep-sided Schöllenen Gorge, below Andermatt; the first wooden bridge across Schöllenen Gorge was built around 1220, in the following years the pass gained in importance. The bridge permitted traffic to follow the Reuss to its headwaters and over the saddle at the top—a continental divide between the Rhine, which flows into the North Sea and the river Ticino towards Milan, which after leaving Switzerland flows into the Po and into the Adriatic Sea.
The Gotthard Pass was known as Monte Tremolo. A chapel dedicated to Saint Gotthard of Hildesheim, considered the patron saint of mountain passes, was built on the southern slope of the pass and consecrated by the archbishop of Milan in 1230; the pass soon became known after the saint, by as early as 1236. The opening of the Schöllenen Gorge for traffic was an important factor in the original Swiss Confederacy; the three regions of Uri and Unterwalden gained imperial immediacy under the Hohenstaufen emperors still in the first half of the 13th century. An important aspect of the early confederacy, expressed in the Pfaffenbrief of 1370, was the guarantee of peace along the road from Zürich to the Gotthard Pass; the Swiss had an interest in extending their influence south of the Alps to secure the trade route across the pass to Milan. Beginning in 1331, they exerted their influence through peaceful trade agreements, but in the 15th century, their involvement turned military. 1403 the upper Leventina, as the valley south of the pass is called, became a protectorate of Uri.
Throughout the 15th century, a changeful struggle between the Swiss and the Duchy of Milan ensued, resulting in the Swiss conquest of the territory of the Ticino. The "Devil's Bridge" legend associated with the crossing of the Schöllenen Gorge is not medieval. A new road, including a tunnel with a length of c. 60 m, was built in 1707/8. The tunnel, known as Urnerloch, was the first road tunnel to be built in the Alps, it was constructed by Pietro Morettini. The path across Schöllenen Gorge, thus across the pass, still carried only foot traffic and pack animals until 1775, when the first carriage made the journey on an improved road; the new Gotthard road was built in 1830, wide enough to allow motorized traffic. With the Gotthard
An endorheic basin is a limited drainage basin that retains water and allows no outflow to other external bodies of water, such as rivers or oceans, but converges instead into lakes or swamps, permanent or seasonal, that equilibrate through evaporation. Such a basin may be referred to as a closed or terminal basin or as an internal drainage system or interior drainage basin. Endorheic regions, in contrast to exorheic regions, which flow to the ocean in geologically defined patterns, are closed hydrologic systems, their surface waters drain to inland terminal locations where the water evaporates or seeps into the ground, having no access to discharge into the sea. Endorheic water bodies include some of the largest lakes in the world, such as the Caspian Sea, the world's largest saline inland sea. Endorheic basins constitute local base levels, defining a limit of erosion and deposition processes of nearby areas; the term comes from the Ancient Greek: ἔνδον, éndon, "within" and ῥεῖν, rheîn, "to flow".
Endorheic lakes are bodies of water. Most of the water falling on Earth finds its way to the oceans through a network of rivers and wetlands. However, there is a class of water bodies that are located in closed or endorheic watersheds where the topography prevents their drainage to the oceans; these endorheic watersheds are called terminal lakes or sink lakes. Endorheic lakes are in the interior of a landmass, far from an ocean in areas of low rainfall, their watersheds are confined by natural geologic land formations such as a mountain range, cutting off water egress to the ocean. The inland water flows into dry watersheds where the water evaporates, leaving a high concentration of minerals and other inflow erosion products. Over time this input of erosion products can cause the endorheic lake to become saline. Since the main outflow pathways of these lakes are chiefly through evaporation and seepage, endorheic lakes are more sensitive to environmental pollutant inputs than water bodies that have access to oceans, as pollution can be trapped in them and accumulate over time.
Endorheic regions can occur in any climate but are most found in desert locations. In areas where rainfall is higher, riparian erosion will carve drainage channels, or cause the water level in the terminal lake to rise until it finds an outlet, breaking the enclosed endorheic hydrological system's geographical barrier and opening it to the surrounding terrain; the Black Sea was such a lake, having once been an independent hydrological system before the Mediterranean Sea broke through the terrain separating the two. Lake Bonneville was another such lake; the Malheur/Harney lake system in Oregon is cut off from drainage to the ocean, but has an outflow channel to the Malheur River, dry, but flows in years of peak precipitation. Examples of humid regions in endorheic basins exist at high elevation; these regions are subject to substantial flooding in wet years. The area containing Mexico City is one such case, with annual precipitation of 850 mm and characterized by waterlogged soils that require draining.
Endorheic regions tend to be far inland with their boundaries defined by mountains or other geological features that block their access to oceans. Since the inflowing water can evacuate only through seepage or evaporation, dried minerals or other products collect in the basin making the water saline and making the basin vulnerable to pollution. Continents vary in their concentration of endorheic regions due to conditions of geography and climate. Australia has the highest percentage of endorheic regions at 21 percent while North America has the least at five percent. 18 percent of the earth's land drains to endorheic lakes or seas, the largest of these land areas being the interior of Asia. In deserts, water inflow is low and loss to solar evaporation high, drastically reducing the formation of complete drainage systems. Closed water flow areas lead to the concentration of salts and other minerals in the basin. Minerals leached from the surrounding rocks are deposited in the basin, left behind when the water evaporates.
Thus endorheic basins contain extensive salt pans. These areas tend to be large, flat hardened surfaces and are sometimes used for aviation runways or land speed record attempts, because of their extensive areas of level terrain. Both permanent and seasonal endorheic lakes can form in endorheic basins; some endorheic basins are stable, climate change having reduced precipitation to the degree that a lake no longer forms. Most permanent endorheic lakes change size and shape over time becoming much smaller or breaking into several smaller parts during the dry season; as humans have expanded into uninhabitable desert areas, the river systems that feed many endorheic lakes have been altered by the construction of dams and aqueducts. As a result, many endorheic lakes in developed or developing countries have contracted resulting in increased salinity, higher concentrations of pollutants, the disruption of ecosystems. Within exorheic basins, there can be "non-contributing", low-lying areas that trap runoff and prevent it from contributing to flows downstream during years of average or below-average runoff.
In flat river basins, non-contributing areas can be a large fraction of the river
Spain the Kingdom of Spain, is a country located in Europe. Its continental European territory is situated on the Iberian Peninsula, its territory includes two archipelagoes: the Canary Islands off the coast of Africa, the Balearic Islands in the Mediterranean Sea. The African enclaves of Ceuta, Peñón de Vélez de la Gomera make Spain the only European country to have a physical border with an African country. Several small islands in the Alboran Sea are part of Spanish territory; the country's mainland is bordered to the south and east by the Mediterranean Sea except for a small land boundary with Gibraltar. With an area of 505,990 km2, Spain is the largest country in Southern Europe, the second largest country in Western Europe and the European Union, the fourth largest country in the European continent. By population, Spain is the fifth in the European Union. Spain's capital and largest city is Madrid. Modern humans first arrived in the Iberian Peninsula around 35,000 years ago. Iberian cultures along with ancient Phoenician, Greek and Carthaginian settlements developed on the peninsula until it came under Roman rule around 200 BCE, after which the region was named Hispania, based on the earlier Phoenician name Spn or Spania.
At the end of the Western Roman Empire the Germanic tribal confederations migrated from Central Europe, invaded the Iberian peninsula and established independent realms in its western provinces, including the Suebi and Vandals. The Visigoths would forcibly integrate all remaining independent territories in the peninsula, including Byzantine provinces, into the Kingdom of Toledo, which more or less unified politically and all the former Roman provinces or successor kingdoms of what was documented as Hispania. In the early eighth century the Visigothic Kingdom fell to the Moors of the Umayyad Islamic Caliphate, who arrived to rule most of the peninsula in the year 726, leaving only a handful of small Christian realms in the north and lasting up to seven centuries in the Kingdom of Granada; this led to many wars during a long reconquering period across the Iberian Peninsula, which led to the creation of the Kingdom of Leon, Kingdom of Castile, Kingdom of Aragon and Kingdom of Navarre as the main Christian kingdoms to face the invasion.
Following the Moorish conquest, Europeans began a gradual process of retaking the region known as the Reconquista, which by the late 15th century culminated in the emergence of Spain as a unified country under the Catholic Monarchs. Until Aragon had been an independent kingdom, which had expanded toward the eastern Mediterranean, incorporating Sicily and Naples, had competed with Genoa and Venice. In the early modern period, Spain became the world's first global empire and the most powerful country in the world, leaving a large cultural and linguistic legacy that includes more than 570 million Hispanophones, making Spanish the world's second-most spoken native language, after Mandarin Chinese. During the Golden Age there were many advancements in the arts, with world-famous painters such as Diego Velázquez; the most famous Spanish literary work, Don Quixote, was published during the Golden Age. Spain hosts the world's third-largest number of UNESCO World Heritage Sites. Spain is a secular parliamentary democracy and a parliamentary monarchy, with King Felipe VI as head of state.
It is a major developed country and a high income country, with the world's fourteenth largest economy by nominal GDP and sixteenth largest by purchasing power parity. It is a member of the United Nations, the European Union, the Eurozone, the Council of Europe, the Organization of Ibero-American States, the Union for the Mediterranean, the North Atlantic Treaty Organization, the Organisation for Economic Co-operation and Development, Organization for Security and Co-operation in Europe, the Schengen Area, the World Trade Organization and many other international organisations. While not an official member, Spain has a "Permanent Invitation" to the G20 summits, participating in every summit, which makes Spain a de facto member of the group; the origins of the Roman name Hispania, from which the modern name España was derived, are uncertain due to inadequate evidence, although it is documented that the Phoenicians and Carthaginians referred to the region as Spania, therefore the most accepted etymology is a Semitic-Phoenician one.
Down the centuries there have been a number of accounts and hypotheses: The Renaissance scholar Antonio de Nebrija proposed that the word Hispania evolved from the Iberian word Hispalis, meaning "city of the western world". Jesús Luis Cunchillos argues that the root of the term span is the Phoenician word spy, meaning "to forge metals". Therefore, i-spn-ya would mean "the land where metals are forged", it may be a derivation of the Phoenician I-Shpania, meaning "island of rabbits", "land of rabbits" or "edge", a reference to Spain's location at the end of the Mediterranean. The word in question means "Hyrax" due to Phoenicians confusing the two animals. Hispania may derive from the poetic use of the term Hesperia, reflecting the Greek perception of Italy as a "western land" or "land of the setting sun" (Hesperia
The Atlantic Ocean is the second largest of the world's oceans, with an area of about 106,460,000 square kilometers. It covers 20 percent of the Earth's surface and about 29 percent of its water surface area, it separates the "Old World" from the "New World". The Atlantic Ocean occupies an elongated, S-shaped basin extending longitudinally between Europe and Africa to the east, the Americas to the west; as one component of the interconnected global ocean, it is connected in the north to the Arctic Ocean, to the Pacific Ocean in the southwest, the Indian Ocean in the southeast, the Southern Ocean in the south. The Equatorial Counter Current subdivides it into the North Atlantic Ocean and the South Atlantic Ocean at about 8°N. Scientific explorations of the Atlantic include the Challenger expedition, the German Meteor expedition, Columbia University's Lamont-Doherty Earth Observatory and the United States Navy Hydrographic Office; the oldest known mentions of an "Atlantic" sea come from Stesichorus around mid-sixth century BC: Atlantikoi pelágei and in The Histories of Herodotus around 450 BC: Atlantis thalassa where the name refers to "the sea beyond the pillars of Heracles", said to be part of the sea that surrounds all land.
Thus, on one hand, the name refers to Atlas, the Titan in Greek mythology, who supported the heavens and who appeared as a frontispiece in Medieval maps and lent his name to modern atlases. On the other hand, to early Greek sailors and in Ancient Greek mythological literature such as the Iliad and the Odyssey, this all-encompassing ocean was instead known as Oceanus, the gigantic river that encircled the world. In contrast, the term "Atlantic" referred to the Atlas Mountains in Morocco and the sea off the Strait of Gibraltar and the North African coast; the Greek word thalassa has been reused by scientists for the huge Panthalassa ocean that surrounded the supercontinent Pangaea hundreds of millions of years ago. The term "Aethiopian Ocean", derived from Ancient Ethiopia, was applied to the Southern Atlantic as late as the mid-19th century. During the Age of Discovery, the Atlantic was known to English cartographers as the Great Western Ocean; the term The Pond is used by British and American speakers in context to the Atlantic Ocean, as a form of meiosis, or sarcastic understatement.
The term dates to as early as 1640, first appearing in print in pamphlet released during the reign of Charles I, reproduced in 1869 in Nehemiah Wallington's Historical Notices of Events Occurring Chiefly in The Reign of Charles I, where "great Pond" is used in reference to the Atlantic Ocean by Francis Windebank, Charles I's Secretary of State. The International Hydrographic Organization defined the limits of the oceans and seas in 1953, but some of these definitions have been revised since and some are not used by various authorities and countries, see for example the CIA World Factbook. Correspondingly, the extent and number of oceans and seas varies; the Atlantic Ocean is bounded on the west by South America. It connects to the Arctic Ocean through the Denmark Strait, Greenland Sea, Norwegian Sea and Barents Sea. To the east, the boundaries of the ocean proper are Europe: the Strait of Africa. In the southeast, the Atlantic merges into the Indian Ocean; the 20° East meridian, running south from Cape Agulhas to Antarctica defines its border.
In the 1953 definition it extends south to Antarctica, while in maps it is bounded at the 60° parallel by the Southern Ocean. The Atlantic has irregular coasts indented by numerous bays and seas; these include the Baltic Sea, Black Sea, Caribbean Sea, Davis Strait, Denmark Strait, part of the Drake Passage, Gulf of Mexico, Labrador Sea, Mediterranean Sea, North Sea, Norwegian Sea all of the Scotia Sea, other tributary water bodies. Including these marginal seas the coast line of the Atlantic measures 111,866 km compared to 135,663 km for the Pacific. Including its marginal seas, the Atlantic covers an area of 106,460,000 km2 or 23.5% of the global ocean and has a volume of 310,410,900 km3 or 23.3% of the total volume of the earth's oceans. Excluding its marginal seas, the Atlantic covers 81,760,000 km2 and has a volume of 305,811,900 km3; the North Atlantic covers 41,490,000 km2 and the South Atlantic 40,270,000 km2. The average depth is 3,646 m and the maximum depth, the Milwaukee Deep in the Puerto Rico Trench, is 8,486 m.
The bathymetry of the Atlantic is dominated by a submarine mountain range called the Mid-Atlantic Ridge. It runs from 87°N or 300 km south of the North Pole to the subantarctic Bouvet Island at 42°S; the MAR divides the Atlantic longitudinally into two halves, in each of which a series of basins are delimited by secondary, transverse ridges. The MAR reaches above 2,000 m along most of its length, but is interrupted by larger transform faults at two places: the Romanche Trench near the Equator and the Gibbs Fracture Zone at 53°N; the MAR is a barrier for bottom water, but at these two transform faults deep water currents can pass from one side to the othe
The Douro is one of the major rivers of the Iberian Peninsula, flowing from its source near Duruelo de la Sierra in Soria Province across northern-central Spain and Portugal to its outlet at Porto. The Latinized name Durius may go back to the name used by the Celtic tribes who inhabited the area before Roman times: the Celtic root is *dubro-. In modern Welsh, dŵr is "water," as well as dour in modern Breton with cognate dobhar in Irish. In Roman times, the river was personified as Durius. Another long-established derivation suggests that the name Douro comes for the Portuguese word for "golden"; the Douro vinhateiro, an area of the Douro Valley in Portugal long devoted to vineyards, has been designated by UNESCO as a World Heritage Site. Traditionally, the wine was taken downriver in flat-bottom boats called rabelos, to be stored in barrels in cellars in Vila Nova de Gaia, just across the river from Porto. In the 1960s and 1970s, dams with locks were built along the river, allowing river traffic from the upper regions in Spain and along the border.
Nowadays Port wine is transported to Vila Nova de Gaia in tanker trucks. In 1998, Portugal and Spain signed the Albufeira Convention, an agreement on the sharing of trans-boundary rivers to include the Douro and Guadiana; the convention superseded an original agreement on the Douro, signed in 1927, expanded in 1964 and 1968 to include tributaries. It is the third-longest river in the Iberian Peninsula after the Ebro, its total length is 897 kilometres, of which only sections of the Portuguese extension below the fall line are navigable, by light rivercraft. In its Spanish section, the Douro crosses the great Castilian meseta and meanders through five provinces of the autonomous community of Castile and León: Soria, Valladolid and Salamanca, passing through the towns of Soria, Almazán, Aranda de Duero and Zamora. In this region, there are few tributaries of the Douro; the most important are the Pisuerga, passing through Valladolid, the Esla, which passes through Zamora. This region is semi-arid plains, with wheat and in some places near Aranda de Duero, with vineyards, in the Ribera del Duero wine region.
Sheep rearing is still important. The drainage basin borders those of Miño to the north, Ebro to the east, Tajo to the south. For 112 kilometres, the river forms part of the national border line between Spain and Portugal, in a region of narrow canyons, it formed a historical barrier to invasions. In these isolated areas, in which the Aldeadávila Dam impounds the river, there are protected areas: the International Douro Natural Park and the Arribes del Duero Natural Park; the Douro enters Portuguese territory just after the confluence with the Águeda River. Except for Porto and Vila Nova de Gaia at the river mouth, the only population centres of any note are Foz do Tua, Pinhão and Peso da Régua. Tributaries here are small. None of these small, fast-flowing rivers is navigable. Major Spanish riverside towns include Soria, Almazán, Aranda de Duero, Tordesillas and major Portuguese towns include Miranda do Douro, Foz Côa, Peso da Régua, Vila Nova de Gaia, Porto; the most populous cities along the Douro River are Valladolid and Zamora in Spain, Porto and Vila Nova de Gaia in Portugal.
The latter two are located at the mouth of the Douro at the Atlantic Ocean. In Portugal, the Douro flows through the districts of Bragança, Viseu, Vila Real and Porto. Porto is the main hub city in northern Portugal, its historic centre has been designated as a UNESCO World Heritage Site because of its significant architecture and history. These reaches of the Douro have a microclimate allowing for cultivation of olives and grapes, which are important for making the famous Port wine; the region around Pinhão and São João da Pesqueira is considered to be the centre of Port wine, with its quintas that extend along the steep slopes of the river valleys. In the 21st century, many of these quintas are owned by multinational wine companies. A prosperous tourist industry has developed based on river excursions from Porto to points along the Upper Douro valley; the Douro railway line was completed in 1887. Pocinho is near the city of Foz Côa, close to Côa Valley Paleolithic Art site; this is considered important to the archaeological pre-historic patrimony, it has been designated as a UNESCO World Heritage Site.
Fifteen dams have been built on the Douro to regulate the water flow, generate hydroelectric power, allow navigation through locks. Beginning at the headwaters, the first five dams are in Spain: Cuerda del Pozo, Los Rábanos, San José, Villalcampo and Castro Dams; the next five downstream are along the Portuguese-Spanish border. The Douro's last five dams are in Portugal, allow for navigation: Pocinho, Valeira, Régua and Crestuma-Lever Dams. Vessels with a maximum length of 83 metres and width of 11.4 metres can pass through the five locks. The highest lock, at Carrapatelo Dam, has a maximum lift of
The Rhône is one of the major rivers of Europe and has twice the average discharge of the Loire, rising in the Rhône Glacier in the Swiss Alps at the far eastern end of the Swiss canton of Valais, passing through Lake Geneva and running through southeastern France. At Arles, near its mouth on the Mediterranean Sea, the river divides into two branches, known as the Great Rhône and the Little Rhône; the resulting delta constitutes the Camargue region. The name Rhone continues the name Latin: Rhodanus in Greco-Roman geography; the Gaulish name of the river was *Rodonos or *Rotonos. The Greco-Roman as well as the reconstructed Gaulish name is masculine; this form survives in the Spanish/Portuguese and Italian namesakes, el/o Ródano and il Rodano, respectively. German has adopted the French name but given it the feminine gender; the original German adoption of the Latin name was masculine, der Rotten. In French, the adjective derived from the river is rhodanien, as in le sillon rhodanien, the name of the long, straight Saône and Rhône river valleys, a deep cleft running due south to the Mediterranean and separating the Alps from the Massif Central.
Before railroads and highways were developed, the Rhône was an important inland trade and transportation route, connecting the cities of Arles, Valence and Lyon to the Mediterranean ports of Fos-sur-Mer, Marseille and Sète. Travelling down the Rhône by barge would take three weeks. By motorized vessel, the trip now takes only three days; the Rhône is classified as a Class V waterway for the 325 km long section from the mouth of the Saône at Lyon to the sea at Port-Saint-Louis-du-Rhône. Upstream from Lyon, a 149 km section of the Rhône was made navigable for small ships up to Seyssel; as of 2017, the part between Lyon and Sault-Brénaz is closed for navigation. The Saône, canalized, connects the Rhône ports to the cities of Villefranche-sur-Saône, Mâcon and Chalon-sur-Saône. Smaller vessels can travel further northwest and northeast via the Centre-Loire-Briare and Loing Canals to the Seine, via the Canal de la Marne à la Saône to the Marne, via the Canal des Vosges to the Moselle and via the Canal du Rhône au Rhin to the Rhine.
The Rhône is infamous for its strong current when the river carries large quantities of water: current speeds up to 10 kilometres per hour are sometimes reached in the stretch below the last lock at Vallabrègues and in the narrow first diversion canal south of Lyon. The 12 locks are operated daily from 5:00 a.m. until 9:00 p.m. All operation is centrally controlled from one control centre at Châteauneuf. Commercial barges may navigate during the night hours by authorisation; the Rhône rises as an effluent of the Rhône Glacier in the Valais, in the Swiss Alps, at an altitude of 2,208 metres. From there it flows south through Gletsch and the Goms, the uppermost, valley region of the Valais before Brig. Shortly before reaching Brig, it receives the waters of the Massa from the Aletsch Glacier, it flows onward through the valley which bears its name and runs in a westerly direction about thirty kilometers to Leuk southwest about fifty kilometers to Martigny. Down as far as Brig, the Rhône is a torrent.
Between Brig and Martigny, it collects waters from the valleys of the Pennine Alps to the south, whose rivers originate from the large glaciers of the massifs of Monte Rosa and Grand Combin. At Martigny, where it receives the waters of the Drance on its left bank, the Rhône makes a strong turn towards the north. Heading toward Lake Geneva, the valley narrows, a feature that has long given the Rhône valley strategic importance for the control of the Alpine passes; the Rhône marks the boundary between the cantons of Valais and Vaud, separating the Valais Chablais and Chablais Vaudois. It enters Lake Geneva near Le Bouveret. On a portion of its extent Lake Geneva marks the border between Switzerland. On the left bank of Lake Geneva the river receives the river Morge; this river marks the border between Switzerland. The Morge enters Lake Geneva at a village on both sides of the border. Between Évian-les-Bains and Thonon-les-Bains the Dranse enters the lakewhere it left a quite large delta. On the right bank of the lake the Rhône receives the Veveyse, the Venoge, the Aubonne and the Morges besides others.
Lake Geneva ends in Geneva. The average discharge from Lake Geneva is 251 cubic metres per second. In Geneva, the Rhône receives the waters of the Arve from the Mont Blanc. After a course of 290 kilometres the Rhône leaves Switzerland and enters the southern Jura Mountains, it turns toward the south past the Bourget Lake which it is connected by the Savières channel. At Lyon, the biggest city along its course, the Rhône meets its biggest tributary, the Saône; the Saône carries 400 cubic metres per the Rhône itself 600 cubic metres per second. From the confluence, the Rhône follows the southbound