Princess Islands.

Quiet heaven of 9 islands in the Marmara Sea only one hour from Istanbul. You can visit 4 of them, no cars allowed, but rental bikes or horse-drawn carriages are available near the ferry landing. The largest, Büyükada, has been a summer retreat for the wealthy for centuries with many monasteries and gorge old waterside mansions. Heybeliada is popular for picnics and strolls, while Sedef is ultra exclusive and only reachable by private vessel (see V. Useful/Turistambul). Ferries leave from Sirkeci and Kabatas(¸Euro side) and Bostanci (Asian side).