Arnala is one of the best forts from coastal forts. it is located in Arnala village, of Vasai taluka. Arnala Fort is also known as ‘Jaldurg’ or ‘Janjire Arnala’. The Arnala was captured by many empires such as Mughals, Marathas, Portuguese, and lastly Peshwas. The sultan Mahmud Begda originally constructed the fort in 1516. There is no source of food but water is available in the well on the fort.
This fort is rectangular in shape and almost surrounded by water. There are many temples such as Tryambakeshwar, Bhavani Mata, Kalika Mata, and also of Mahadev. There are three entrances out of which one entrance has big bastions on both sides which are at north side of fort.