Sindhudurg Fort, located on an island off the Malvan coast, was built in 1664 under Chhatrapati Shivaji to protect the Maratha Empire and is significant for its strategic role during various colonial encounters. The fort features a 30 ft high wall, intricate architecture with a zig-zag design, and houses several temples, including one dedicated to Shivaji. Accessible via boats from Malvan, its scenic beauty and historical importance make it a must-visit site.