Fortification
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A fortification is a military construction designed for the defense of territories in warfare, and is used to establish rule in a region during peacetime. The term is derived from Latin fortis ("strong") and facere.
Castillo San Felipe del Morro, Puerto Rico. The fortress and walled city of Old San Juan are a UNESCO World Heritage Site.
Castillo San Felipe de Barajas, Colombia. Cartagena's colonial walled city and fortress were designated a UNESCO World Heritage Site.
Maiden Castle in 1935. The Iron Age hillfort was first built in 600 BC.
Early 20th century aerial photograph of the fortifications of Valletta, Malta, which were built in the 16th and 17th centuries.
Earthworks (engineering)
Videos
Earthworks are engineering works created through the processing of parts of the earth's surface involving quantities of soil or unformed rock.
Caterpillar D10 bulldozer at work
Retaining wall types
Soil nailing
Tieback