Padmadurg

Padmadurg, also known as Kasa fort, is one of five historical sea forts built by Chhatrapati Shivaji Maharaj and located in Raigad District Maharashtra, India. It was built by Shivaji Maharaj to keep look over Janjira fort, as it was attempted many times by the Portuguese and other invaders from Janjira, which was controlled by the Siddis. It also served as a key shipbuilding yard during Shivaji's reign. Now partly in ruins, Padmadurg remains accessible via special permission and is protected under the Archaeological Survey of India, with ongoing efforts to conserve its unique maritime heritage.

Fort data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).