I went on to take a one day trip to Dhanuskodi, Tamilnadu off from Madurai. Take any train journey to Rameshwaram and that's where you cross a hell of a rail-bridge, the more than '100 years old' Pamban bridge which connects you to the Rameshwaram Island.
I dare you feel the sea underneath your feet on a slow moving train on Pamban. Exotic!!!
Plus you get a beautiful glimpse of the Pamban road bridge alongside.