The city of Poseidonia was founded at the end of the 7th century BC. The Temple of Ceres was built around 500 BC and is an outstanding example of temple architecture for the period of transition between late Archaic and the dawn of Classicism. The Temple of Neptune is from the 5th century. Other finds include a basilica, a pool, the Ecclesiasterion, the Amphitheater, the residential areas and several tombs. The archaeological site was declared a World Heritage site by UNESCO in 1998.