Rameswaram is located near the Gulf of Mannar which separates Rameswaram Island with Mannar in Srilanka. Rameswaram island is in the shape of a Conch (Shanku) and is connected with Indian mainland via the Pamban Bridge. According to the Hindu Puranas, upon the advice of Rishis (sages), Rama along with Sita and Lakshmana, installed and worshiped the Sivalinga here to expiate the sin of Brahmahatya (killing of a Brahmin).(Ravana, the son of Vishrava and the great grandson of Brahma). Rama fixed an auspicious time for the installation and sent Anjaneya to Mount Kailas to bring a lingam. As Anjaneya could not return in time, Sita herself made a linga of sand. When Anjaneya returned with a linga from Mount Kailas the rituals had been over. To comfort the disappointed Anjaneya, Rama had Anjaneya’s lingam (Visvalingam) also installed by the side of Ramalinga, and ordained that rituals be performed first to the Visvalingam. More information on Rameswaram can be found on the Wikipedia Link