The Alfeiós or Alpheios is the main stream of the Alpheios Valley drainage system, a dendritic type, originating on the north slopes of Mount Taygetus, located in the center of the Peloponnesus of Greece, and flowing to the northwest to the vicinity of Olympia, where it turns to the west and, after being impounded by the Flokas Dam, a hydroelectric facility, empties into the Gulf of Kyparissia of the Ionian Sea south of Pyrgos. The entrance into the gulf through agricultural land and across an unpopulated, sandy beach partially blocked by a spit is hydrologically unspectacular, with the water too shallow to be navigable by any but the smallest craft.

The Peloponnese, Peloponnesus or Morea is a peninsula and geographic region in Southern Greece, and the southernmost region of the Balkans. It is connected to the central part of the country by the Isthmus of Corinth land bridge which separates the Gulf of Corinth from the Saronic Gulf. From the late Middle Ages until the 19th century, the peninsula was known as the Morea, a name still in colloquial use in its demotic form.