Arnala Fort

Arnala Fort stands on a small island off the port of Arnala, about 13 kilometres north of Vasai, where the Vaitarna river meets the sea, giving it command of the whole bay. Also called Jaldurg or Janjire Arnala, it has been a protected monument since May 1909. The Portuguese built a bastion here in 1530 and later began a larger fort they never finished, but held the island for two centuries to control shipping along the north Konkan coast.

In 1737 Chimaji Appa, brother of Peshwa Baji Rao I, was sent to capture Bassein from the Portuguese. His general Shankarji Pant urged an attack on Arnala as well. A first assault, supported by Maratha ships under Govindji Kasar and Manaji Angre, was beaten off by the Portuguese navy, but a surprise attack on 28 March 1737 forced them to abandon the island, and the Marathas then built the present fort.