Eski Cami was begun in 1403 by Emir Sulevman and completed in 1414 by Mehmed I. Haci Alaaddin from Konya is the architect of the mosque. It is a perfect square building measuring 49.50 m. per side. Four huge square piers support nine equal domes (13.5 m. in diameter). Simple squinches, stalactites and Turkish triangles effect the txansition to the domes of the centre row. Pendentives support the other six. The middle dome before the door was originally over an inner court with fountain. This part has been closed. The dome topping the court originally had an oculus, later replaced by a lantem. There is a portico preceded by an open space in front of the mosque.