- Khubladha or Thal fort is situated on the coast of Thal near Alibaug. This was meant to protect Underi fort.The fort was built on a natural elevation on the Thal coast. In 1659, when Shivaji Maharaj started building Khanderi fort, Khubladha played a major role as offshore base for men and material. Also, this was to protect any invasion on the land from British and Siddis. In 1749, Siddi conquered the fort. However, Manaji Angre got it back in 1750 in a battle where 200 people of Siddi were killed. Later, since the fort became more vulnerable to attacks, it was abandoned and the base was moved to Colaba fort of Alibaug.