The Sri Ranganathaswamy Temple occupies most of Srirangam island and is one of the most important pilgrimage sites in South India. The temple is dedicated to Ranganatha, the reclining form of Lord Vishnu — the deity here lies on the cosmic serpent Adi Shesha in a pose of divine rest. The main idol in the innermost sanctum is considered one of the 108 divya desams, the holiest Vishnu shrines in the Vaishnava tradition.
Seven concentric enclosure walls surround the complex, each entered through a gopuram tower. The outermost enclosures contain streets, shops, and homes — a functioning neighbourhood integrated into the temple precincts. Non-Hindu visitors may enter the outer five enclosures freely; the inner two are restricted. The 1,000-Pillared Hall (Ayiram Kaal Mandapam) in the fourth enclosure has remarkable carved columns, each different. The Rajagopuram, the main southern gateway tower at 73 metres and 13 tiers, is the tallest temple tower in Asia — it was started in the 14th century and finally completed in 1987. Dress modestly; clothing is available for hire at the entrance if needed.