Iznik Yakup Çelebi Mosque and Tomb
It was built by Yakup Çelebi, the son of Murat I. The building consists of entrance and worship spaces extending consecutively in the north-south direction, two side wings adjacent to the entrance in the east and west, and the last congregation place in the north. Its outbuilding is 500 m² and its interior area is 290 m². The mosque has a square plan and a triangular dome. It opens to the outside with seven windows: two bases symmetrically on the south side, a top window on the axis, and a bottom window on the east and west walls. The covering system of the walls is plastered. The entrance frame and wings are made of wood. The exterior walls are built with one row of cut stone and three rows of bricks in an alternating technique. The mosque has been renovated in various periods. The last time it was opened for worship was 1961. In the north-east of the mosque, 5 km away from the final congregation place, there is the mausoleum of Yakup Çelebi in the garden.