Varkala Tunnel is a popular tourist highlight for its magnificent construction which was done by digging varkala hill in 1880. It was a 924 ft(277 meters) long tunnel built in 1867 by the then dewan of Travancore(Attingal Palace) T.Mahadeva Rao , and took around 15 years to complete at an expense of 1.7 million Indian rupees This tunnel opens to varkala’s TS canal which runs on the side of Sivagiri mutt, and is a standing symbol of Kerala’s forgotten trade route to ferry people and goods between Trivandrum & Quilon(Kollam) and commercial past. Some unorganised trips to the canal brings a strange feeling among the travelers. Etched out under a cliff, this century-old tunnel is about 41 kilometers (25.6 miles) from Trivandrum. A huge vent on the roof opens up this dark underground structure to fresh air and sunshine.