The ruined Adina Mosque (1374–75) is very large, which is unusual in Bengal, with a barrel vaulted central hall flanked by hypostyle areas. It is said to be the largest mosque in the sub-continent, and modeled after the Ayvan-e Kasra of Ctesiphon, Iraq, as well as the Umayyad Mosque of Damascus. The heavy rainfall in Bengal necessitated large roofed spaces, and the nine-domed mosque, which allowed a large area to be covered, was more popular there than anywhere else. After the Islamic consolidation of Bengal was complete, some local features continued, especially in smaller buildings, but the Mughals used their usual style in imperial commissions.