Thane Creek is an inlet in the shoreline of the Arabian Sea that isolates the city of Mumbai from the Indian mainland. It comprises the area between Mumbra Retibunder and the Mankhurd-Vashi Bridge. The creek is divided into two parts. The first part lies between Ghodbunder and Thane, a section from where the Ulhas river flows from the north of Mumbai Island to meet the Arabian Sea on the west. The second part of the waterway lies between the city of Thane and the Arabian Sea at Trombay, before the Gharapuri islands. In antiquity, Thane served as the capital of the Sheelavahan kingdom, and was a large functional port for trade with the Arabian peninsula, along with other ports, such as Ghodbunder and Nagla Bunder. The region of the Thane Creek has been recognized as an Important Bird Area by the Bombay Natural History Society, as it is home to various avian species. In particular, it harbors populations of flamingos and several other migratory and wading birds.