Dha'ra'vi island, on the west of Salsette at the mouth of the Bassein creek, has, on a ridge of hill, the ruins of a large Portuguese church and the remains of a fort. The church was noticed as a ruin by Anquetil du Perron in 1760. About twenty years later Dr. Hove described the fort as situated on the highest hill in the island, with only a front and a hind wall and no guns but only English colours. At the foot of the hill close to the river side a battery of eight guns had been raised since the last war (1774). Dharavi has some curious and excellent quarries of basalt columns which are separated by the crowbar. Much of the Bassein fort seems to have been built of this stone, and this is probably the Bassein stone of which many of the chief buildings in Goa are made. The Dharavi hill has many springs whose water was formerly used for irrigation by the Portuguese. The water is now carried in pipes to the Rai-Murdha salt-works.