Located approx. 4.9 miles from Alibaug near Thal, the Underi Fort and its sister fort Khanderi were once the largest and major defences during the Maratha rule. Served as a sturdy protector against the Siddi and the British in the 17th-century, this sea fort still stands tall in the Arabian Sea. Most visitors come to enjoy the picturesque setting and gaze upon the fortification wall, which is over 400-years-old. This sea fort can only be visited during low tide via small boat from the Thal beach; while Khanderi fort can be visited anytime of the year.
