Ancient Thera was founded in the 9C BC on a magnificent site high above the Aegean Sea. It was a sizeable city in Antiquity with 5 000 inhabitants and 700 cisterns and reached the height of its importance under the Egyptian Ptolemies (300-150 BC), who established a naval base here. Thera declined under the Romans and was abandoned in the 13C. The ruins include the Temenos of Artemidoros; the agora; the Temple of Apollo; the Terrace and the Gymnasium of the Ephebes.