Vattakottai, literally meaning circular fort, is an 18th century granite fort. It was built by King Marthanda Varma to serve as defense for Nanjil Nadu. Located 6 km north-east of Kanyakumari
, Vattakottai overlooks the sea and is an ideal tourist spot.
Vattakottai has a rectangular shape and covers an area of about four acres. It is enclosed by 25 to 26 feet high walls, including the parapet of 29 feet thick at the front, 18 feet at the corners and 6 feet at the rear. A well can be seen on the northern side of the fort. There is a small river by the side of the fort. Besides, the fort has a subway or tunnel of about four feet width, which connects the fort to Padmanabhapuram Palace.
Evidences left by the fort itself specify that it served as a military base to protect the Kanyakumari port which was a rich pearl harbor. The emblems of fish in the fort substantiate that it was under the control of the Pandyas for sometimes. The lighthouse in Leepuram, named after Colonel Lee, is a nearby attraction.