Arnala Fort

Arnala Fort is located approximately 8 miles North of Vasai. It is built on a small island off the Arnala port. Since the fort is built on an island and surrounded on all sides by water it is also known as "Jaldurg" or "Janjire Arnala" Portuguese called the island "Ilha das vocas". Before the Portuguese control of the island, the island was controlled by the Muslim rulers of Gujarat.
The island is near the mouth of Vaitarna river and the Portuguese used it to observe and control shipping and navigation along the western coast. The Portuguese captain of Bassein donated the island to a Portuguese nobleman. The nobleman tore down the old fort and began construction of 700 foot by 700 foot fort. The fort was never completed by the nobleman but remained under Portuguese control.
In 1737 when Chimaji Appa began his assault on Bassein (Vasai) to drive out the Portguese, his General Shankarji Pant informed Chimaji that Arnala fort is a strategic for the naval forces that
were on route to attack the Portguese. Chimaji approved the assault on the fort. Shankarji Pant consulted and sought assistance of the local people to attack the Arnala fort; among them were Govindji Kasar and Gavraji Patil from Bolinj. Shankarji sent Gangaji Naik, Bajirao Belose and Rayajirao Surve to lead a battalion of 400 soldiers to lead the attack on Arnala fort. This attack was coordinated along with naval force commanded by Manaji Agre. Maratha navy was no match for the Portuguese firepower. Agre's navy was routed.
On March 28, 1737 Maratha forces attacked the fort and surprised the Portuguese who were caught with their guard down. The Portuguese retreated and gave up the fort. The Maratha victory was commemorated with a plaque installed on the northern wall of the fort and is still visible today.
Soon after the Maratha victory, Shankarji Pant began reconstruction of the fort. By January of 1738 three bastions were completed. The three bastions were named Bahirav, Bhavani and Bava. The construcation was completed by March of 1738.