Sedir Island is the biggest of the three islands in the Gokova Gulf. There are ruins worth seeing on the island. Its ancient name is Kedrae or Cedrae. City walls and towers, Apollo Temple and the church that were built later, theatre , agora and the ancient port ruins of Sedir Island should be seen. Kadrae was one of the most important Carian city since the 6th century BC. According to some resources, the families of the kings spent their summer months on this island. It is known that it became one of the towns of Rhodes in later centuries. To get to Sedir Island there are boats from Akyaka town (Ula district of Mugla province) and Camlı area of Gelibolu Village in Marmaris.