Rama's Bridge or Rama Setu, also known as Adam’s Bridge, is a long, twisting stretch of shoal and sandbank connecting the Indian island of Rameswaram, off the southeastern coast of Tamil Nadu, to Mannar Island, off the northwestern coast of Sri Lanka. The bridge is about 50 km long. Much of it is under water today, but centuries ago, it formed an intermittent, but otherwise solid, connecting link between India and Sri Lanka. The causeway existed as late as the 15th century and was passable on foot, as per records kept at the Rameswaram temple, until it was flooded in a storm.
The existence of the bridge has been known in India as well as Sri Lanka since ages, as evident from the legend perpetuated by the ancient epic of Ramayana. For as long as anybody could remember, the sea separating the two countries has been called Sethusamudram meaning "Sea of the Bridge". The 9th century Persian geographer, Ibn Khordadbeh, mentioned the bridge in his Book of Roads and Kingdoms, referring to it is Set Bandhai or "Bridge of the Sea". The name “Adam’s Bridge” is an early-19th-century British invention —a reference to an Abrahamic myth that Adam used the bridge to cross from Sri Lanka to India.