According to the Ramayana, after Rama defeated the demon-king Ravana in Lanka and rescued his wife Sita, he was troubled. Ravana, despite his villainy, was a Brahmin, and killing a Brahmin carried the stain of Brahmahatya. On the advice of sages, Rama installed and worshipped a lingam, the iconic symbol of Shiva, on this island to absolve his sin. He sent his trusted lieutenant Hanuman to the Himalayas to bring a suitable lingam, but when Hanuman took too long, Sita fashioned one from the sand of the nearby seashore. That sand lingam is believed to be the one still enshrined in the temple's sanctum. The story links Rameswaram to the great arc of the Ramayana narrative, making it not just a place of worship but a place where even a god sought penance.

The Ramanathaswamy Temple dominates the center of town. It is one of the 12 Jyotirlinga shrines, where Shiva is worshipped as a pillar of light, and one of the 275 Paadal Petra Sthalams glorified in hymns by the great 7th-century Nayanar saints Appar, Sundarar, and Tirugnana Sambandar. The temple's current structure dates to the 12th century, built by the Pandya Dynasty, though rulers kept adding to it for centuries afterward. Its most striking feature is its corridors, the longest of any Hindu temple in India, lined with sculpted pillars in the Nayak style that echo the grand Meenakshi Amman Temple in Madurai. Even the rulers of Sri Lanka contributed: Parakrama Bahu, who reigned from 1153 to 1186 CE, was involved in building the sanctum sanctorum. The Sethupathy dynasty of the 17th century poured resources into the temple, and the statue of Muthu Ramalinga Sethupathy still stands at the entrance to the corridor he built.

The pilgrimage to Rameswaram revolves around water. Of the 64 sacred water bodies in and around the town, the Skanda Purana identifies 24 as particularly important, and 22 of those are tanks within the temple itself. Pilgrims move from tank to tank, immersing themselves in each, a ritual considered equivalent to years of penance. The foremost is Agni Tirtham, where the sea meets the shore. Others carry names from the Ramayana: Jatayu Tirtham, where the vulture demigod Jatayu is said to have fallen after Ravana severed his wings; Hanuman Tirtham; Sugriva Tirtham. At Villoondi Tirtham, about seven kilometers from the main temple, Rama is believed to have quenched Sita's thirst by dipping his bow into the sea. The highest point on the island is Gandhamathana Parvatham, a hillock three kilometers north of the temple, where Rama's footprints are venerated in a two-story hall.

Rameswaram occupies a peculiar geography. The Pamban channel separates it from mainland India, crossed now by the New Pamban Bridge, which replaced India's first sea bridge. The railway terminus connects it to Chennai and Madurai, threading trains across the open water. To the southeast, the island narrows to a sandy point at Dhanushkodi, where the chain of shoals known as Adam's Bridge stretches toward Sri Lanka. The Gulf of Mannar to the southwest is rich with marine life, including coral reefs, dugongs, and sea turtles. Fishing has sustained the island's economy for centuries, and the waters around Rameswaram still yield prawns, lobsters, sea cucumbers, and chanks, the sacred conch shells prized across India. The island sits at the intersection of devotion and livelihood, where pilgrims and fisherfolk share the same shoreline.

Rameswaram's most famous modern son was born here in 1931. A. P. J. Abdul Kalam, the son of a local boat owner, grew up in a modest household near the Ramanathaswamy Temple. He would go on to lead India's missile development program, earning the title "Missile Man of India," before being elected the 11th President of India in 2002. A Muslim scientist who became president of a Hindu-majority nation, Kalam embodied the secularism and meritocracy that India aspires to. He died in 2015 while delivering a lecture in Shillong, and his family insisted he be buried in his hometown rather than at a state memorial in New Delhi. His memorial in Peikarumbu, designed by India's Defence Research and Development Organisation, now draws visitors alongside the ancient temple.