Bombay Castle or the Manor House was the nucleus of the physical and administrative growth of the city and was built by Garcia da Orta, a Portuguese physician and botanist in the 16th(1550's) century as a permanent wooden structure. It stands on the western coast of the city and exactly behind the Town Hall i.e Asiatic Library. The Instrument of Possession that facilitated the transfer of Bombay from the Portuguese to the British was signed here in the year 1666. In the year 1668 the East India Company shifted its headquarters from Surat and to the Castle. Subsequent to this, the British fortified the remains of the Manor House and renamed it as Bombay Castle and re-built it, using the locally available blue Kurla stone and red laterite stone from the Konkan region.
When Gerald Aungier took over the governship of Bombay he drew a plan of fortification of the town as Castle constituted its nucleus by housing the Governor's office, the treasury and the artillery stores. The Governor house was shifted from here to Parel later. From 1715, for a very short period, Bombay Law Court functioned from Bombay Castle. During the 18th century the Castle was structurally strengthened and aided with 100 canons. In 1830 Bombay Castle became the Headquarters of the Indian Navy, which was constituted form the old Bombay Marine. For few decades it was abandoned but post independence it was handed over to the Navy and renamed as INS Angre in the year 1951. Bombay Castle holds what are perhaps some of the oldest structures and building in Bombay. Presently its out of bound for the general public as assess to it is highly restricted.