Sri Veeraraghava Perumal Temple

Temple tradition traces the "Vaidya" epithet to the sage Salihotra, who is said to have bathed daily in the temple's tank, believed to cure ailments of the body. The legend's best-known episode involves an old, ailing Brahmin guest who arrived seeking the sage's hospitality; when Salihotra, testing the depth of the guest's own faith, asked a probing question (traditionally rendered as "Uraivatharku ivvul evvul?" (roughly, "how much space is needed here to stay?")) the guest's reply and the exchange that followed is said to have revealed the visitor's true form: Vishnu himself, reclining as Anantashayana upon the serpent Adishesha. The place-name legend holds that this exchange, built around the word "evvul," gave the settlement its original name, Thiru Evvul Oor, which evolved over time into today's Thiruvallur.

The healing association carried by the "Vaidya" epithet has made this temple a particular pilgrimage destination for devotees seeking relief from illness, a devotional niche distinct from most other Divya Desams in the region.

The temple's origins are generally placed in the late 8th and 9th century CE, during the Pallava period, with the earliest surviving inscriptions dating to the latter half of the 9th century, consistent with the wider wave of Pallava temple-building across the Thondai Nadu region documented at nearby Divya Desams. The temple subsequently received significant contributions from the Cholas, the Vijayanagara Empire, and later the Thanjavur Nayaks, each of whom left their mark through mandapas, structural additions, and endowments.

Among the temple's Chola-period inscriptions is one recording a grant of 1,000 kulis of land by Tiruvenkatadeva during the reign of Kulothunga Chola I (1070–1122 CE), while another inscription on the eastern wall of the Vahana Mandapam records a gift of 130 pons of gold made between 1630 and 1675 by Veera Raghava Sadagoppa Jiyar, the thirteenth pontiff of the Ahobila Matha, evidence of continued Sri Vaishnava institutional patronage at the temple well into the early modern period.

The sanctum, built in the Vijayakoti Vimanam style, houses Veeraraghava Perumal in the reclining (sayana) posture associated with the Salihotra legend. The temple tank, Hritabhanasini Pushkarini (whose name is popularly linked to the removal of sin or affliction ("hrith-thapa-nasini," roughly "remover of heart's suffering")) remains an active part of the pilgrimage today, tied directly to the healing tradition the temple is known for.

The temple's Vahana Mandapam, which carries one of the site's notable Ahobila Matha inscriptions, forms part of the wider complex added during later centuries of dynastic and institutional patronage, alongside the sanctum's Pallava-era core.

A ten-day Brahmotsavam held in the Tamil month of Chittirai (March–April) is the temple's most prominent annual festival, during which the utsavar is carried in procession through the streets around the temple on a different vahanam each day, culminating in a chariot festival and a float festival (theppotsavam) on the tank on the closing days, the same Chittirai timing and format shared with several other Thondai Nadu Divya Desams, including nearby Thirunindravur.

Given the temple's association with healing, many devotees also time personal visits around the belief in the curative power of a bath in the Hritabhanasini tank, a practice that continues alongside the temple's formal festival calendar rather than being confined to a single festival date.

Daily worship follows the standard two-session Agamic schedule, with archana and abhishekam offered to Veeraraghava Perumal in his reclining form; the healing association carried by the "Vaidya" epithet means that personal prayers for recovery from illness are an especially common feature of everyday darshan here compared to many other Divya Desams.

Special abhishekams and more elaborate rites are reserved for the Chittirai Brahmotsavam and other major festival days, when the temple sees considerably larger crowds than its everyday suburban-rail pilgrim traffic.