Here is your short paragraph on Rameshwaram:
Rameshwaram is one of the four dhamas, the ‘abodes’ of the gods. In the far South, at the tip of India in Tamil Nadu, is the dhama of Rameshvaram.
Here it was that Lord Rama, with the help of the monkey armies, built the great bridge to the island of Lanka where the wicked Ravana held Sita in captivity.
When he had killed Ravana, Lord Rama returned to Rameshvaram and established a linga there as a penance for killing Ravana, who was a brahmin as well as a demon and whose death incurred for Rama the terrible sin of killing a brahmin.
The linga Rama established came to be considered one of the great lingas of light so holy that it destroys the worst sins by merely beholding it.