Mannar Island formerly spelled as Mannar Island, is part of Mannar District, Sri Lanka. It is linked to the main island of Sri Lanka by a causeway. It has an area of about 125 square kilometres, mainly covered with vegetation and sand. Adam's Bridge, is a chain of limestone shoals, between Pamban Island, also known as Rameswaram Island, off the southeastern coast of Tamil Nadu, India, and Mannar Island, off the northwestern coast of Sri Lanka. Geological evidence suggests that this bridge is a former land connection between India and Sri Lanka.
Between 1914 and 1964, there was a train and ferry link from mainland India via Dhanushkodi and Talaimannar to Colombo, but this was not resumed after the disastrous damages caused by a cyclone in 1964. The Palk Strait bridge was proposed in June 2015, to link mainland India to Mannar.