This site was constructed by the Travancore Kingdom to establish a continuous inland waterway across Thiruvithamkoor as TS Canal, which was meant to serve as a trade route.

[1] With a length of 1,069.848 metres (0.664773 mi), the two tunnels played a vital role in transferring ferry goods and people from the capital city of Trivandrum to Kollam during the pre-independence era.

The tunnel is located under the main cliff of the region and represents the architectural excellence of the workers and engineers of that era.

[2] Built under the supervision of then chief engineer Walthew Clarence Barton during reign of T. Madhava Rao, the Dewan of the Travancore Kingdom, the tunnel also makes up for the major man made reach i.e. Varkala stretch of Thiruvananthapuram–Shoranur canal, which passes through a delicate geological structure.

The Government of India has turned down Kerala's demand to extend the existing National Waterway 3 route to Kovalam from Kollam through Varkala.