Lisbon From Saint George Castle Gardens, Portugal Stock Photo

Saint George Castle is a Moorish castle occupying a commanding hilltop overlooking the historic centre of the Portuguese city of Lisbon and Tagus River. The strongly fortified citadel dates from medieval period of Portuguese history, and is one of the main tourist sites of Lisbon. Although the first fortifications on this hilltop date from the 2nd century BC, archaeological excavations have identified a human presence in the Tagus valley as far back as the 6th century BC. The first fortification was, presumably, erected in 48 BC, when Lisbon was classified as a Roman municipality. The hill was first used by indigenous Celtic tribes, then by Phoenicians, Greeks, and Carthaginians as a defensible outpost that was later expropriated by Roman, Suebic, Visigothic, and Moorish peoples. During the 10th century, the fortifications were rebuilt by Muslim Berber forces, these included the walls or Cerca Moura `Moorish Encirclement`.