According to an old Urdu account, the original Jama Masjid of Mumbai was located near Dongri. It was later detached and erected at Esplanade. In 1770, this mosque too was demolished by an order of Governor William Hornby which forbade the survival of any building within 600 years of the walls of the Fort.
The construction of the present Jama Masjid ongoing in 1775 but work on it could not be completed till 1802. The Masjid is a quadrangular pile of brick and stone encircled by a ring of terraced roofed and double storeyed buildings.
The main eastern gate leads to an very old tank filled with about 10 feet of water. From the depths of the tank rise 16 black stone arches which support the whole fabric of the mosque.