Pigeon Island is the symbol of Kusadasi. The island is place of birds during the seasonal migrations that are why it was named Bird Island.
Island is one of the best places to watch the panoramic view of the beautiful city and enjoy watching the sunset. You can also sip your drink at one of the cafe in the island and with scenery.
The Island was used for securing the shores or preverted the attacks from the sea. The Byzantine Castle is standing on the rocks and used against pirates.
Reference:http://www.kusadasi.com/