Just off Kusadasi harbor, a 350-meter-long causeway leads out to charming Pigeon Island, where the remnants of a 13th-century Byzantine fortress (which later became a pirates' lair) sit on the cliff.
The rampart walls, which wrap partially around the island, are a later addition dating to the early 19th century. Pigeon Island is a favorite spot for a seaside walk, and there is a lovely café here as well. This is the place to come for an early evening promenade and to admire the sunset.