Iznik pottery
The ceramic collection of the Topkapi Palace includes over ten thousand pieces of Chinese porcelain but almost no Iznik pottery. Most of the surviving Iznik vessels are in museums outside Turkey, but examples of the city's tile production exist in numerous cities throughout Turkey, such as İstanbul, Bursa, Edirne and Adana. In Istanbul examples of Iznik tiling can be seen in mosques, tombs, libraries, and palace buildings, such as the Rüstem Pasha Mosque, the Sokollu Mehmet Pasha Mosque, the tomb of Selim II in the Hagia Sophia complex, and certain buildings of the Topkapı Palace complex such as the Circumcision room and the Baghdad Kiosk.
Topkapı Palace
The square Tower of the Head Tutor ("Başlala Kulesi"), also known as the Chamber of the Chief Physician and court drugstore ("Hekimbaşı Odası ve ilk eczane"), dates from the 15th century, and is the oldest building in the Fourth Courtyard. It was built as a watch tower, probably during the time of Mehmed II. It has few windows, and its walls are almost two metres thick. The physician had his private chamber at the top, while below was a store for drugs and medicine.