The Kolaba Fort is situated 2 km away from the shores of Alibag in the Konkan Region. This old military fort was fortified by Shivaji Maharaj in 1662. The fort was controlled by Darya Sagar and Manik Bhandari who led the Maratha attacks on the British ship. In 1713, the fort was handed over to Kanhoji Angre, the first chief of the Maratha Navy, under the treaty signed with Peshwa Balaji Vishwanath.The walls of the fort measure around 25 ft and has two main entrances, one facing the sea and the other facing Alibag. The Siddhivinayak Temple inside the Kolaba Fort was constructed in 1759 by Raghoji Angre.