The length of the Bosphorus, which separates the continents of Asia and Europe, is thirty kilometers. The distance between the Anatolian Lighthouse and the Maiden's Tower is about thirty-five kilometers. Adalar (the Islands) is a district of İstanbul which includes nine islands: Büyükada, Heybeliada, Burgazada, Kınalıada, Sedefadası, Sivriada, Yassıada, Kaşık Adası, and Tavşan Adası. The center of the district of Adalar is Büyükada. The district was called the Princes' Islands as it was a site for exiled palace members, particularly in the Byzantine Era.


This island, with an area of 420 hectares, is the center of the district. It was called Prinkipo in the past. The highest point of the island is Yücetepe (the Hill of Hagia Yorgi). The Hagia Yorgi Monastery is visited by tens of thousands of people from different religion,s particularly on the 23rd of April and the 24th of September. It is a beautiful district with its peaceful environment as well as old buildings and manor houses built from stone, wood or both. Anadolu Kulübü (Anatolian Club), Büyükada Su Sporları Kulübü (Büyükada Water Sports Club), and “the Olympic Facilities” are important facilities of the island.


This isalnd is covered with pine forests and it has an area of 240 hectares. The oldest known name of Heybeliada is Halky (copper). The highest point of the island is Değirmen Tepesi, which is 136 meters high. Çam Limanı is the widest bay, not only of Heybeliada but also of all the islands. The most important symbol of Heybeliada is the Old Naval School. The Old Cleric School (presently the Private Greek Senior High School) is also an important structure in Heybeliada. Terki Dünya and the Cleric School (Private Greek Senior High School) are the structures which are mostly visited by foreign tourists. Heybeliada Mosque, the only mosque on the island, was built between 1935 and 1936. The Olympic facilities of Heybeliada Water Sports Club and the promenade site of the island are particularly interesting sites.


Burgazada is the third biggest island. Its oldest known name is Antigoni. İsa Tepesi, the highest point of the island, is 170 meters high. Its slopes are covered with pine plantations. It has beautiful and small beaches on its shores. The Hristos Monastery, Hagia Yani Church and its Holy Spring, Avusturya Saint Georges Hastanesi (Austrian Saint Georges Hospital), and the Ayios Yeoris Monastery are the most important historical structures on the island. The facilities of the Water Sports Club are also important.


This island has an area of 110 hectares. It was called Porty in the past. Its highest point is Çınar Tepesi (115 m). Hristos Monastery, the Armenian Church, cisterns, and the old quarries are worth seeing. Its mosque, built in a modern architectural style, attracts attention. The facilities of the Water Sports Club, which also includes an Olympic pool, are important assets of the island. The district of Adalar also includes Sedefadası, which has a beautiful public beach; Kaşıkadası which is presently a private property; Tavşanadası and Sivriada which are rocky islands; and Yassıada on which military facilities are established. Residents of the islands have been fishing and farming throughout history. Vineyards, fruit gardens and vegetable orchards made the islands a pharmaceutical warehouse. Regular boat service since 1846 also increased the level of interest in the district.