NALA SETHU

Talaimannar, situated at the tip of Mannar Island, is where Nala Sethu (Adam's Bridge) - the string of coral reefs, shoals and shifting sandbanks that connect India with Sri Lanka - begins. This bridge was allegedly built by the monkey-general Hanuman, who then crossed over from India with his simian army in a series of giant leaps to rescue Sita.
The above Space images were taken by NASA appears above. Reveal a mysterious ancient bridge in the Palk Strait between India and Sri Lanka. The recently discovered bridge currently named as Adam’s Bridge is made of chain of shoals, c.18 mi (30 km) long. The bridge’s unique curvature and composition by age reveals that it is man made.
Certain historical inscriptions, old travel guides, old dictionary references and some old maps have reinforced the religious and geographical belief of this structure being the ancient bridge that is considered with great regard by the Hindus in the Indian sub-continent. This conjecture must be tempered with the fact that there are no geographical pointers to the structure being Rama's Bridge in any of the ancient texts or Puranas. Vaishnava News Network and some other U.S.-based news services suggested that it had discovered the remains of the bridge built by Rama and his Vanara army, that is referred to in the Ramayana, and that it was not a natural formation, basing their claim on 2002 NASA satellite footage... NASA distanced itself from the claims saying that what had been captured was nothing more than a 30 km long, naturally occurring chain of sandbanks. It also clarified that, "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 team from the Centre for Remote Sensing (CRS) of Bharathidasan University, Tiruchi led by Professor S.M. Ramasamy in 2003 claimed that the, "Rama's bridge could only be 3,500 years old" and, "as the carbon dating of the beaches roughly matches the dates of Ramayana, its link to the epic needs to be explored". However, one needs to note that the surveys which have come out with 3500 age for the bridge are based on the studies conducted on corals grown on the bridge itself and it has been argued that this represents only the age of what was measured, which is the corals. The bridge underneath the corals has been dated back to hundreds of thousands of years earlier.
A former Director of the Geological Survey of India,
S. Badrinarayanan claims that such a natural formation would be impossible; He justifies the same by the presence of loose sands layer under corals for entire stretch. Corals normally form above rocks.” He feels that thorough analysis was not conducted by Geological Survey of India before undertaking SSCP project. In connection with the canal project, the Madras High Court in its verdict stated that the Rama Sethu is a man-made structure. Geological and archaeological findings of Teri formations, rich assemblage of Mesolithic-Microlithic tools and human fossils found on both sides of the bridge by Department of Earth-Science in March 2007 are also quoted as evidence for manmade structure.
Prof. N. Ramanujam, Head, Post Graduate Department of Geology and Research Centre, V.O. Chidambaram College, astrophysicist Jayant Narlikar and a group of professors of Madurai Kamaraj University (which is in the state of Tamil Nadu and is directly under the control of the state ministry of education) stated that Rama's bridge is a natural geographical feature which formed some 17 million years ago.. In addition, Archaeological Survey of India has said that the structure is not man-made. A government publication from National Remote Sensing Agency, which was recently tabled in the Indian Parliament, says that the structure "may be man-made".