Thane is a metropolitan city located on the northwestern side of the state of Maharashtra in India and on the northeastern side of Mumbai. It is an immediate neighbour of Mumbai city proper, and a part of the Mumbai Metropolitan Region. It is situated in the north-eastern portion of the Salsette Island. Thane city is situated entirely within Thane taluka, one of the seven talukas of Thane district. It serves as the headquarters of the district.