Didim is a district and municipality in Aydin Province, Turkey. It is a well-known coastal vacation destination located on the Aegean shore of western Turkey, 123 kilometers from the provincial capital Aydin. Didim is the location of the ancient city of Didyma, featuring the remains of the Temple of Apollo. Didim is situated on the northern coast of the Gulluk Gulf, facing villages on the Bodrum peninsula like Torba, Turkbuku, and Yalikavak. In ancient times, this was known as the Posideium Peninsula, but sediment from the Meander River has later filled the inlet to its north, more completely linking it to the mainland.
The district of Didim includes Didim along with several small towns such as Altinkum, Gumuskum, and Sarikum. Its neighboring areas include Soke to the north-east and Milas to the south-east. Tourism serves as the primary income source for the region, particularly during summer, although agriculture also plays a significant role; the principal crops include cotton and wheat.
The development of Didim during the 1980s was further sped up with the construction of hotels to host tourists, initially from Britain but now from Turkey itself, on affordable package vacations. Since around 2000, Britons have started purchasing summer homes in Didim, forming a notable community of thousands, so much so that utility bills in the area are now issued in both English and Turkish.