The Princes’ Islands (Turkish: Prens Adaları), are a chain of nine islands off the coast of Istanbul, in the Sea of Marmara. They consist of four larger islands, Büyükada ("Big Island") with an area of 5.46 sq km, Heybeliada ("Saddlebag Island") with an area of 2.4 sq km, Burgazada ("Fortress Island") with an area of 1.5 sq km, Kınalıada ("Henna Island") with an area of 1.3 sq km, and five much smaller ones, Sedef Adası ("Mother-of-Pearl Island") with an area of 0.157 sq km, Yassıada ("Flat Island") with an area of 0.05 sq km, Sivriada ("Sharp Island") with an area of 0.05 sq km, Kaşık Adası ("Spoon Island") with an area of 0.006 sq km, and Tavşan Adası ("Rabbit Island") with an area of 0.004 sq km.
During the summer months the Princes’ Islands are a popular destination for day trips from Istanbul. As there is no traffic on the islands, the only transport being horsecarts, they are incredibly peaceful compared with the bustling city of Istanbul. They are just a short ferry ride away, with ferries departing from Bostancı, Kartal and Maltepe on the Asian side, and from Kabataş on the European side. Most ferries stop in turn at all the four largest of the nine islands: Kınalıada, Burgazada, Heybeliada and finally Büyükada. In spring and autumn the islands are quieter and more pleasant, although the sea can be sometimes rough, and the islands are sometimes cut off from the outside world. In winter, when it is also very cold with strong winds, the islands become almost deserted.
During the Byzantine period, princes and other royalty were exiled on the islands, and later members of the Ottoman sultans’ families were exiled there too, giving the islands their present name. They were taken by the Ottoman fleet during the siege of Constantinople in 1453. In the 19th century, the islands became a popular resort for the wealthy of Istanbuk, and Victorian-era cottages and houses are still preserved on the largest of the islands.
Büyükada (meaning "Big Island") is the largest of the nine islands. As on the other islands, motorized vehicles – except service vehicles – are forbidden, so visitors explore the island on foot, by riding a bicycle or in horse-drawn phaeton carriages which function like taxis, also offering "round-the-island" sightseeing tours.
A convent on Büyükada was the place of exile for the Byzantine empresses Irene, Euphrosyne, Theophano, Zoe and Anna Dalassena. After his deportation from the Soviet Union in February 1929, Leon Trotsky also stayed for four years on Büyükada. Princess Fahrelnissa Zeid was born on the island.
There are several historical buildings on Büyükada, such as the Ayia Yorgi Church and Monastery dating back to the 6th century, the Ayios Dimitrios Church, and the Hamidiye Mosque built by Abdul Hamid II. Büyükada consists of two peaks. The one nearest to the iskele (ferry landing), Hristos, is topped by the former Greek Orphanage, a huge wooden building now in decay. In the valley between the two hills are the church and monastery of Ayios Nikolaos and a former fairground called Luna Park. Visitors can take the 'small tour' of the island by buggy, leading to this point, from where it is an easy climb to Ayia Yorgi, a tiny church with a cafe on the grounds serving wine, chips and sausage sandwiches, this being part of the "classic" Ayia Yorgi (St. George, in Greek: Άγιος Γεώργιος) experience.