Ram Setu: The Ancient Bridge Between India and Sri Lanka

Stand at the end of the road at Dhanushkodi, on the eastern tip of Pamban Island in Tamil Nadu, and on a clear day you can see a line of pale sandbanks running out towards Sri Lanka. That line is Ram Setu. It is a chain of shallow limestone shoals about forty-eight kilometres long, partly dry and partly just under the water, stretching across to Mannar Island. Hindus revere it as the bridge built by Lord Rama’s army in the Ramayana; geologists, who call it Adam’s Bridge, study it as a natural formation.

Ram Setu aerial view between India and Sri Lanka

Both views have long histories, and the two do not always sit easily together. Below you will find what the Ramayana says, what surveys and satellite images show, why a shipping canal through the shoals became a national controversy, and how to see Ram Setu for yourself.

Where is Ram Setu?

Ram Setu runs from near Dhanushkodi on Pamban Island in India to Talaimannar on Mannar Island in Sri Lanka. It separates the Gulf of Mannar to the south from Palk Bay to the north. The water over the shoals is usually between one and ten metres deep, and in a few places small sandbars break the surface.

The name Adam’s Bridge comes from a different tradition. In some Islamic and Christian accounts, Adam crossed from Sri Lanka to the mainland this way after being cast out of paradise. British mapmakers used that name, and it is still the one on most international maps.

Ram Setu in the Ramayana

In the Ramayana, Ravana carries Sita away to Lanka. Rama, with his brother Lakshmana and an army of vanaras led by Sugriva and Hanuman, marches south to rescue her. At the southern shore the sea blocks their way.

Rama spends three days in prayer to the god of the ocean (Samudra, often identified with Varuna), asking for passage. When there is no answer, he grows angry and raises his bow to dry up the sea. The ocean god then appears and tells him that the vanara Nala, son of the divine architect Vishwakarma, can build a bridge across.

In Valmiki’s telling, the vanaras haul rocks, trees and boulders into the sea under Nala’s direction, and the bridge is finished in five days. In many later and regional retellings, Nala and his companion Nila carry a blessing that whatever they place in the water will float, and the stones are inscribed with Rama’s name. The army crosses, Ravana is defeated, and Sita is freed.

This is the version most Indian children hear at home or watch in the Ramleela. It is why the shoals are sacred to millions of Hindus, and why any plan to alter them has drawn such strong feeling.

What geologists say about Ram Setu

Most geologists describe Ram Setu as a natural formation. In this view, India and Sri Lanka sit on the same continental shelf and were joined by dry land during the last ice age, when sea levels were much lower. As the ice melted and the sea rose, the land link was submerged, and over thousands of years coral, sand and pebbles collected along the shallow ridge that remained.

Satellite images, including ISRO’s, show the chain of shoals very clearly, and one widely shared image from the early 2000s made it look almost like a road across the sea. The Geological Survey of India and the Central Marine Fisheries Research Institute have surveyed the area. Their broad finding is that the shoals are natural deposits of coral and sand on top of an older ridge.

Not everyone accepts that this settles the question. Some Hindu scholars and organisations argue that the formation, or parts of it, could be man-made and want further study. Others see no conflict: for them a natural ridge used by Rama’s army is entirely consistent with faith. A satellite image cannot answer what the Ramayana means to a believer, and a belief does not change how coral grows, so the two accounts often run side by side.

Could people once walk across Ram Setu?

Historical accounts suggest that parts of the shoal could be crossed on foot until about the fifteenth century. A cyclone around 1480 is commonly said to have deepened the channels and submerged the last walkable stretches. Medieval references to people crossing on foot are cited in support, though the details are hard to confirm.

The Sethusamudram shipping canal controversy

Ships travelling between India’s west and east coasts currently have to sail around Sri Lanka, because the water at Ram Setu is too shallow. In the 2000s the government took up the Sethusamudram Shipping Canal Project, which planned to dredge a channel through the shoals to shorten the route.

Hindu groups strongly opposed cutting through a structure they consider sacred. Environmentalists and fishing communities raised separate concerns about the coral reefs and fisheries of the Gulf of Mannar, and some shipping experts questioned whether the canal would pay for itself.

The Supreme Court of India stayed work on the Ram Setu alignment in 2007. Later hearings and government reviews looked at alternative routes that would leave the shoals untouched. The canal has not been built, and there have also been petitions asking for Ram Setu to be declared a national heritage monument.

How to see Ram Setu from Dhanushkodi

You cannot walk on Ram Setu today. You can see its northern end from Dhanushkodi, about eighteen kilometres from Rameswaram town. The road ends at a point called Arichal Munai, where the land narrows to a strip of sand with Palk Strait on one side and the Gulf of Mannar on the other. Looking out from there, the shoals continue as a pale line towards Sri Lanka.

Dhanushkodi was a busy railway and ferry town until the night of 22-23 December 1964, when a cyclone destroyed most of it. The ruins of the church, the railway station and the post office still stand in the sand and are worth a stop on the way.

Most visitors combine the trip with Rameswaram, which is a major pilgrimage centre. Its Ramanathaswamy Temple is one of the twelve Jyotirlingas, and tradition links its linga to Rama’s worship of Shiva at this spot.

How to reach Rameswaram

The nearest airport is Madurai, about 170 kilometres away. Rameswaram has its own railway station on the Southern Railway network, with direct trains from Chennai and Madurai.

Rail and road reach the island over the Pamban bridges. The old Pamban rail bridge, opened in 1914, was India’s first sea bridge, and a new vertical-lift rail bridge alongside it was opened in 2025.

From Rameswaram, local buses, taxis and jeeps run to Dhanushkodi. Go early in the morning, when the light is soft and the wind is lighter, and avoid the October-December monsoon if you can. November to February is generally the most comfortable period.

Frequently Asked Questions

Is Ram Setu man-made or natural?

Most geological surveys describe it as a natural ridge of coral, sand and limestone. Many Hindus believe it is the bridge built by Rama’s army, and some argue for further study of whether parts are man-made.