Yassıada

Yassıada (Greek: "Plati") is one of the Princes' Islands in the Sea of Marmara. The island, which has an area of 0.05km², is officially a neighbourhood in the Adalar district of Istanbul, Turkey.

Yassıada (Plati) was used by the Byzantines for sending prominent figures into exile. One such person was the Armenian Patriarch (Catholicos) Narses who was first sent to this island before being imprisoned at Büyükada (Pringipos) in the 4th century. In the 11th century, the Byzantines used the island for political prisoners. The remains of the four underground prison cells from this period can still be seen. The Byzantines also built a monastery and church on the island. Yassıada (Plati) was captured by the Latin Crusaders during the Fourth Crusade in 1204.

In 1857, the island was purchased by the British ambassador Henry Bulwer, brother of novelist Edward Bulwer-Lytton, who built himself a mansion and a small castle-like structure to live undisturbed on this distant island. The tiny castle and the wharf in front of it are still standing today. Henry Bulwer also organized agricultural production on the island to self-sustain his little kingdom at least to a certain degree, but later sold Yassıada to the Ottoman Khedive, Ismail Pasha, in whose ownership the island fell into a period of neglect.

With the establishment of the Turkish Republic in 1923, the island became a property of the Turkish state, and in 1947, Yassıada was handed over to the Turkish Navy which built several school buildings.

Yassıada later became the site of the trials of Demokrat Parti members, after the military coup of 1960. Several of the defendants were sentenced to death, and three of these, including the former Prime Minister of Turkey Adnan Menderes, were executed. Upon the conclusion of the trials, Yassıada was given back to the Turkish Navy, for use in training and naval exercises until 1978.

In 1993, the island became a property of Istanbul University's department of Marine Life and Sea Products, which used it for training and research. However, the island's strong winds made the work difficult for students there, and the University took the program elsewhere.

Today, the island is a favourite location for scuba diving schools, as well as amateur divers.