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.
The Jama Mosque is a quadrangular structure of brick and stone, encircled by a ring of terrace roofed and double storeyed buildings, the ground floors of which are let out as shops. The chief or eastern gate of the mosque leads directly across an open courtyard to the ancient tank, which is now furnished with masonry steps and embankments, built in 1893, and contain about ten feet of water fed by springs at the bottom, that contains gold and silver fish and few turtles. This is used for ritual ablutions (wudu), however modern facilities are also available for this purpose.