Rameswaram, which has Ramanathaswamy ,a form of Lord Shiva is a Holy Place for Hindus.
People take bath in the 22 Theerthas and in the sea, Bay Of Bengal to expiate their sins.
It is believed that Lord Rama built
a Bridge here to cross over to Lanka to bring Sita back.
On return He worshiped Lord Shiva in the form of a Linga.
He asked Hanuman to bring a shiva Linga to worship but as the auspicious time was running out a Shiva
Linga was made out of sand by Sita and Rama worshiped it.
He also took bath in the Theerthas.
While Valmiki mentions about Rama building a bridge from near Rameswaram, his Ramayana is silent on Rama’s worship of Shiva Linga there.
However this is narrated by Veda Vyasa in his Adyatma Ramayana.
. Rama also speaks about the merit of Pilgrimage to Rameswara in the Adhyatma Ramayana.