Didyma (; ) was an ancient Greek sanctuary on the coast of Ionia in the domain of the famous city of Miletus. Apollo was the main deity of the sanctuary of Didyma, also called Didymaion. But it was home to both of the temples dedicated to the twins Apollo and Artemis. Other deities were also honoured within the sanctuary. The Didymaion was well renowned in antiquity because of its famed oracle. This oracle of Apollo was situated within what was, and is, one of the world's greatest temples to Apollo. The remains of this Hellenistic temple belong to the best preserved temples of classical antiquity. Besides this temple other buildings existed within the sanctuary which have been rediscovered recently; a Greek theatre and the foundations of the above-mentioned Hellenistic temple of Artemis, to name but two. Geography The ruins of Didyma are located a short distance to the northwest of modern Didim in Aydın Province, Turkey, whose name is derived from the ruins. It sits on a headland that in antiquity formed the Milesian Peninsula. Didyma was the largest and most significant sanctuary on the territory of the great classical city Miletus. The natural connection between Miletus and Didyma was by way of ship. But during antiquity the sediments from the Meander River silted up the harbour of Miletus. A slow process which eventually meant that the nearby Latmian Gulf developed from a bay into a lake (today Bafa Gölü). The linear distance between Miletus and Didyma measures some 16 km. As well as the simple footway there also existed a Sacred Way between the city and its sanctuary which measured some 20 km in distance. This Sacred Way, built in the 6th century BC, was used for festival processions. It touched the harbour of Didyma, situated 3 km northwest of the sanctuary called Panormos (today Mavişehir). Along this route were ritual waystations, and statues of noblemen and noblewomen, as well as animal and mythological beast figures. Some of these statues, dating to the 6th century BC, are now in the British Museum (Room 13), excavated by the British archaeologist Charles Thomas Newton in the 19th century. The Milesians erected an altar dedicated to Poseidon 6 km southwest of Didyma. The altar was built in the first half of the 6th century BC at the southwest cape of the Milesian Peninsula. Here was the border between Ionia and Caria (according