Agrigento rises on the slopes of a mountain plateau between the basins of the Sant'Anna River and the San Biagio River. It was probably founded in the 6th century BC. The religious buildings in the site include the Sanctuary of the Chthonic Divinities and the Temple of Heracles from the 6th century BC, the temples of concordia, of Castor and Pollux and of Juno Lacinia from the 5th century BC and the Temple of Zeus. Several tombs were also found. The archaeological area of Agrigento was declared a World Heritage site by UNESCO in 1997.