The feature is 48 kilometre long and separates the Gulf of Mannar from the Palk Strait . Some of the regions are dry, and the sea in the area rarely exceeds 1 metre in depth, thus hindering navigation. It was reportedly passable on foot until the 15th century when storms deepened the channel. Ramnath swami Temple records say that Adam's Bridge was entirely above sea level until it broke in a cyclone in 1480.
The bridge starts as a chain of shoals from the Dhanushkodi tip of India's Pamban Island. It ends at Sri Lanka's Mannar Island. Pamban Island is accessed from the Indian mainland by the 2 kilometre long Pamban Bridge. Mannar Island is connected to mainland Sri Lanka by a causeway.
The lack of comprehensive field studies explains many of the uncertainties regarding the nature and origin of Adam's Bridge. It mostly consists of a series of parallel ledges of sandstone and conglomerates that are hard at the surface and grow coarse and soft as they descend to sandy banks. The Marine and Water Resources Group of the Space Applications Centre of the Indian Space Research Organisation concludes that Adam's Bridge comprises 103 small patch reefs. One study tentatively concludes that there is insufficient evidence to indicate eustatic emergence and that the raised reef in southern India probably results from a local uplift.
The ancient Sanskrit epic Ramayan mentions a bridge constructed by the god Raam with aid from an army of Banar Sena to reach Lanka and rescue his wife Sita from Raban. In popular belief, Lanka is equated to present day Sri Lanka and the bridge is held to be created by Raam, however, Sanskrit sources of the first millennium often make an explicit distinction between the two and this connotation appears to have been promulgated only in the tenth century by the Chol rulers of South India seeking a cause to invade the island before being co-opted by the Aryacakrabarti dynasty of Jaffna who highlighted themselves as guardians of the bridge.
Controversy over origin claims:
Religious beliefs that the geological structure was constructed by Raam have caused some controversy as believers reject the natural provenance of Adam's Bridge. S. Badrinarayanan, a former director of the Geological Survey of India, a spokesman for the Indian government in a 2008 court case, the Madras High Court, and an episode from the Science Channel series What on Earth? have claimed that the structure is man made.
In the What on Earth? episode, those claiming that Adam's Bridge was constructed based their arguments on vague speculation, false implications, and the point that as with many geological formations not every detail of its formation has been incontrovertibly settled. Indian Geologist C. P. Rajendran described the ensuing media controversy as an "abhorrent" example of the "post-truth era, where debates are largely focused on appeals to emotions rather than factual realities".
NASA said that its satellite photos had been egregiously misinterpreted to make this point during the protests against Sethusamudram Shipping Canal Project. NASA noted: "The images reproduced on the websites may well be ours, but their interpretation is certainly not ours. Remote sensing images or photographs from orbit cannot provide direct information about the origin or age of a chain of islands, and certainly, cannot determine whether humans were involved in producing any of the patterns seen."
A report from the Archaeological Survey of India found no evidence for the structure being anything but a natural formation. The Archaeological Survey of India and the government of India informed the Supreme Court of India in a 2007 affidavit that there was no historical proof of the bridge being built by Raam. In 2017 the Indian Council of Historical Research announced a pilot study into the origins of the structure, but went on to shelve it.
In 2007, the Sri Lankan Tourism Development Authority sought to promote religious tourism from Hindu pilgrims in India by including the phenomenon as one of the points on its "Ramayan Trail", celebrating the legend of Prince Raam. Some Sri Lankan historians have condemned the undertaking as "a gross distortion of Sri Lankan history". The idea of Raam Setu as a sacred symbol to be appropriated for political purposes strengthened in the aftermath of protests against the Sethusamudram Shipping Canal Project.