Kodungallur is situated on the banks of the periyar river , where it joins the arabian sea. In anicient india it was one of the largest & important harbour.Kodungallur was known as one of the four gates to india along with chennai on the east coast , calcutta in the north east & mumbai in the west.It had trade relations & cultural exchanges with civilizations likeRome, Babylonia, Egypt, Phoenica , Alexandra, Arabia, China, Siam & Greece. An average 100 ships were said to be operating from the harbour of kodumgallur.

At present Kodungallur has been reduced to an insignificant village interms of modern development.A flood in 1341 is said to be the reason for its destruction and trade relations with the outside world .