This 18th century circular fort overlooking the sea is worth visiting. There are watch towers, rest rooms and weapon rooms. Well laid stairs lead up to an arch in the front wall, set with a tiny square peephole. Centuries ago when the area around the fort was clear, observers could see right up to Padmanabhapuram Palace. It is said that there was a 4ft wide tunnel from the fort to the palace, a distance of nearly 25 km. The fish motif, symbolizing the Pandya kings is engraved on many of the walls. The Dutch General DeLennoy and his navy attacked the fort when it was under Marthanda Varma and were defeated. They surrendered to Marthanda Varma and De Lennoy became one of Varma's most faithful Generals. The raised parade ground overlooks the Bay of Bengal on one side and the Arabian Sea on the other. On the Arabian Seaside, the water is calm, and the sand is streaked with the red and brown of copper and uranium. The Bay of Bengal appears rougher, with tiny coral clusters visible just under the water's surface.