As a working cathedral, visitors are welcome to stop in for Mass (in both English and Tamil), though the church draws large crowds for Mass. After visiting the main cathedral, view the tomb of St. Thomas in the underground Tomb Chapel, accessible from outside the main church structure. Another structure on the grounds houses a small museum containing artifacts related to St. Thomas and a theater showing a video about his life. Most Mylapore walking tours also stop at the cathedral.
The cathedral is situated in Chennai’s Mylapore neighborhood, one block inland from the Foreshore Estate Promenade, which runs along the coast. The Mundaka Kanni Amman Koil and the Thirumayilai Railway Station are each about a 20-minute walk away from the church, while the famous Kapaleeshwar Temple is about 10 minutes away on foot.
The cathedral is open daily, with Mass on Sunday (check ahead for English service schedules). If you aren't interested in attending a service and want to avoid crowds, you're best off visiting during the week. The annual Feast of St. Thomas is also celebrated here, with activities starting in late June and going through early- to mid-July (his official feast day is July 3rd).
Although the San Thome Cathedral is Chennai’s most famous church, it’s certainly not the only one worth visiting. Other noteworthy churches include the nearby Church of Our Lady of Light, AKA the Luz Church (also built in the 1500s), the historic (and now defunct) Armenian Church, and the stately St. George’s Cathedral built by the British in the early 19th century.