Varadaraja (Devaraja) of Kanchi — great Vishnu of Tondai-mandalam
The 108 Divya Desams are the sacred abodes of Vishnu sung by the 12 Alvar saint-poets. Compiled as the Nalayira Divya Prabandham by Nathamuni (9th c. CE), this corpus of 4,000 pasurams defines the sacred geography of Tamil Vaishnavism and the Sri Vaishnava sampradaya.
One of the 3 holiest Vishnu temples in South India (with Srirangam and Tirumala). Ramanuja, Vedanta-desika, Swami Manavala-mamunigal all served here. The Atti-Varadar (fig-wood icon) submerged in the temple tank is raised once every 40 years — last 2019, next 2059.
Daily 5-fold puja; Vaikuntha Ekadashi (Margazhi full moon) is the holiest day — the Paramapada-vasal gate is opened; passing through is said to grant moksha. Annual Brahmotsavam (10 days) features Vishnu on all his vahanas (Garuda, Hanumanta, Shesha, Hamsa, Simha, Ratha).
Each Divya Desam's sanctity rests on how many Alvars sang of it and how many pasurams — this is the mangalashasanam. Tamil Vaishnavism treats the 4,000 pasurams as Dravida Veda — equivalent to the Sanskrit Vedas.