Princes' Islands (Büyükada)
Adalar municipality lists nine islands (Büyükada, Heybeliada, Burgazadası, Kınalıada, Sedef Adası, Yassıada, Sivriada, Kaşık Adası and Tavşan Adası), and İETT's island lines serve Büyükada, Heybeliada, Burgazada and Kınalıada. Büyükada, the largest at 5.4 square kilometres and 2,300 metres off the Maltepe coast, has about 9,000 residents (2025 census) and two or three times that in summer. Its two hills are Yücetepe (203 metres) in the south and İsa Tepesi in the north. The Aya Yorgi church and monastery stand on the highest point, with a first structure on the site dated to the 6th century, and the island has five mosques, including the Hamidiye Mosque built by Abdülhamid II. The municipality describes a big tour around the island and a small tour from Araba Meydanı to Dilburnu, and names Yörükali and Nizam beaches. Istanbul Metropolitan Municipality's planning office says motor vehicles have never been used on the islands except for public services, that the horse-drawn phaetons were withdrawn in January 2020, and that electric buses and taxis have carried the public since July 2020; İETT's July 2020 announcement named the island lines (BA-1 to BA-3 on Büyükada, HA-1 and HA-2, BU-1, KA-1) and said non-resident passengers pay with an İstanbulkart. In 2026 the municipality banned entry to forest areas from 8 June to 15 October, and asked that swimming take place only in designated areas.
Getting there: The district governorate lists Bostancı, Kadıköy, Kartal and Kabataş as the mainland piers, with additional summer sailings from Bakırköy, Avcılar and Pendik. The Istanbul Metropolitan Municipality planning office counts close to 140 daily sailings at the summer peak, about 76.5% by private operators, and names Kabataş, Eminönü, Bostancı, Kartal and Kadıköy as the busiest departure points. The 2025 Şehir Hatları announcement listed municipal island lines from Kabataş, Beşiktaş, Bostancı and Tuzla-Pendik and nightly Bostancı-Adalar ring sailings. XTOUR could not open the operators' own timetables, so check the day's last return sailing on arrival.
Distance
Büyükada is about 2,300 metres off the Maltepe shore of the Asian mainland
Best season
The municipality says summer day visitors and holiday residents push Büyükada's population to two or three times its winter figure, and the 2026 forest-entry ban ran 8 June to 15 October; roads, the village, the coast and beaches are not covered by it.