Sindhudurg fort is located on a small island surrounded by the Arabian Sea near the shore of Malvan. The fort is spread across 48 acres. It was envisioned by Chhatrapati Shivaji Maharaj, the founder of the Maratha Empire, and built by Hiroji Indulkar, the chief architect of many forts built under the Maratha rule. The construction started in 1664, and it took nearly three years to complete it. The fort was programmed to be the headquarters of the Maratha Navy and provide protection to the people. It took 100 architects and manpower of 3000 to complete the construction of the fort in 1667.
The state of Maharashtra has a varied historical background as many rulers have tried to conquer this land for generations. Many of them had ignored the naval arm of their military forces as they were focusing on strengthening their land boundaries. But the scenario changed when the Portuguese arrived. As there is the vast Arabian sea covering the western part of the state, it had become necessary to protect the kingdom not only from the enemies that would encroach the land via the oceans. Shivaji Maharaj, a defense strategist and visionary, understood the importance of having a naval force and started building the Maratha navy around 1657-59. After many failed attempts of conquering the Murud Janjira Fort that was under the reign of Siddis, Maharaj thought of building a new fort that would serve as the Maratha Naval Headquarter. Apart from the Portuguese, the Arabian Sea was not under any commanding influence. At that moment, Maharaj identified a stranded island named Kurte Bet as it was an ideal base for building a strong naval fort.
Shivaji Maharaj had exceptional reasoning behind the construction of forts. As Sindhudurg was built on an abandoned island, it was prone to attacks from the invaders. Hence, for the security of the fortress and the people living in it, Shivaji Maharaj built small fortresses on the coast named Padmadurg, Rajkot, and Sarjekot. The fort has a four km long zigzag line of 9 meters high and 3 meters wide rampart with 42 bastions. The shape of the fortress is irregular with many projecting points and deep indentations, thus offering the command of all the sides. Over 4000 pounds of iron were used in the casting and foundation stones were firmly laid down in lead. Shivaji Maharaj set up a quarry on the island itself rather than transporting it from the shore to get the stones for construction. A remarkable feature of the fort is its entrance. It is difficult to identify the entrance gate from outside. The gate is built in between 2 bastions and the pathway is so narrow that only 4-5 people can enter through it at one time. In case of an attack, by the time the opposition army could enter through the pathway, Maratha soldiers on the top of the bastions would have already killed them there itself.
Another entrance is located at the Ranichi Vela that opens up to a beach. Another significant feature of the fort was the Nishan Buruj. It is known by many names like Nishan Kathicha Buruj, or Flag Bastion, or Jhenda Buruj. It was mainly used to unfurl the Maratha Flag. Usually, the flag was unfurled on the gate of any fort. But in Sindhudurg, it is placed in the central portion so that it would be visible from any direction. One can imagine the nobility of a kingdom when a person could see the infinite sea, the incessant walls of the fort, and the Bhagawa or the orange colored Maratha Flag soaring high in the sky. An interesting yet curious element of the fortress was the hidden underwater passage. Yes, an underwater passage built in the 17th century!!! The passage begins from a temple that looks like a water reservoir. It goes under the fort for 3kms. From this point, it is underwater and further opens up in a village that is 12 km away.
The fort has three sweet water wells named Dudh Baav (Milk Well), Sakhar Baav (Sugar Well), and Dahi Baav (Curd Well). These sweet water wells never dry up even when all the water reservoirs near the coast evaporate in the summers. This fort houses the only temple dedicated to Shivaji Maharaj that has a statue and original sword of Maharaj. There are also domes built on the palm and footprints of Shivaji that had been accidentally embedded in the lime during construction. All these relics have been preserved by the next generations that resided in the fort. Shivaji Maharaj was not an ordinary king, his brilliant contemplation and diplomatic outlook towards his people and the kingdom made him a true Emperor due to which he is still worshipped in the whole state of Maharashtra.
Today, there are lakhs of people who visit the fort just to admire the ideology and craftsmanship of this architectural marvel built in the middle of the sea. The ferries take people from the coast to the fortress. The fort is closed to tourists for three months during monsoon. Even today, there are at least 15-20 families that still live in the fort precinct. It is maintained by the Archeological Survey of India and the Government of Maharashtra. Sindhudurg is undoubtedly an unparalleled and unique fort in various dimensions.