The name of the mosque Synyk-Kala is translated as destroyed tower. It was built by the architect Muhammad ibn Abu Bakr. This is the earliest architectural monument, not only in Baku and Apsheron peninsula, but throughout Azerbaijan. Arabic inscription on a stone slab at the entrance to the mosque belongs to the 471 year of the Muslim Hegira calendar (1078 - 1079). In architectural terms Synyk-Kala is a two-tiered installation. The specifics of construction is that the mihrab has the shape of half-cylinder and goes beyond the outer line of the wall. Illumination inside the mosque is faint, as it`s provided by the only stained-glass window and dull light of several lamps. Currently, the mosque tours are available. But in accordance with Muslim law, the entrance to the mosque is allowed only to men. To get to the mosque you have to go through a very low vaulted arch, which is typical for all mosques in the Icheri-Shahar. This is done specifically to ensure that everyone who enters the mosque bows his head before God.