Rama Setu which is also called Adam's bridge is built by Vanara Samuha(Monkeys' group) on the order of Lord Sri Rama. Nala is the architect who is descendent of Vishwakarma designed this bridge. This is built with limestone shoals which are chained to each other. It is located between Pamban Island also called Rameswaram Island, the south-eastern coast of TamilNadu, India and Mannar Island, the northwestern coast of SriLanka. It is proven geologically that this bridge the former land connection between SriLanka and India.
The bridge measure 18 miles almost 30 kms long. This bridge is the separation between Palk Strait(northeast) and the Gulf of Mannar(southwest). The sea here is very shallow with a depth of 3 ft to 30 ft(1m to 10 m) where the navigation hindered and some sandbanks are dry.In 15th century, people use to pass by foot until unless it is deepened by the storms and the records in the temple say that Ramasetu is completely above the sea level till it was broken by a cyclone in 1480 CE.
The floating stones are from Rameswaram which are used to construct RamaSetu to cross the sea in order to reach SriLanka. It was clearly stated in ancient text 'Valmiki Ramayana-Yudhakanda 6.22.50 -72. Wood from variety of trees are used as foundation of the bridge on the top the trees large stones were arranged in sequential order.
- In 2005 Indian UPA Govt. launched Sethusamudram Shipping Channel Project which aimed to clear the bed of Ramasetu by scooping out mud. But Supreme Court in 2007 involved to stop this process to protect Ramasetu and Hindu religious beliefs.
- A British cartographer in 1804 prepared a map on this bridge which called this bridge Adam's bridge. This is probably named referring Islamic Island which Adam used to reach Adam's peak in SriLanka, where he stood on a single foot for hundreds of years leaving a footprint mark of the same. The peak and the island are named after this legend, Adam.
- In Skanda Purana an interesting point was described that there is a installation of three Shiv-lings at the beginning, middle and end of the RamSetu.
- Many politicians commented on Lord Rama history and Ramasetu origin.
- Ramasetu was built by Vanaras in 5days as per valmiki ramayana. Lord Rama called this bridge as Nala-Setu on the name of engineer but people called it as Ramasetu, SetuBandhanam while generations passed.
- According Atomic Energy commission scientist's there exist large quantity of that radioactive element available below Ramsetu. Which produces 4 Lac Mega watts of electricity every hour for the next 150 years.
- There is a scientific proof behind these floating stones not to float.These floating stones do have air cavities inside i.e., the air is trapped when formation itself and so the density is very less in water. To be simpler, these stones weigh lesser when compared to other rocks of same size. If the density of a thing is lesser to water then it will float, it is the nature. These stones float 10% above the water, it means the weight of this rocks are 10-20% less than the normal rocks of the same size. Currently, this bridge is covered with an iron mesh. This gives an example of air cavity theory.
- Limestone's will float in salt water(impure) and they sink in normal water(pure).