San Thome Basilica is a white neo-Gothic church that stands on the Mylapore coast, beside the sea at the southern end of Marina Beach. The basilica was elevated to cathedral status in 1956 and to minor basilica status in 2006, but its significance predates all these designations: it is said to be built over the tomb of the Apostle Thomas.
The crypt beneath the altar contains the tomb and a small museum with relics associated with St Thomas, including a bone fragment displayed in a glass case. Whether the historical basis for Thomas's Indian mission is solid or legendary remains debated among historians, but the site has been venerated for at least 1,500 years — a Portuguese church stood here in 1523, and there are references to earlier structures.
The current building dates to 1896 and is a confident piece of Victorian neo-Gothic, with pointed arches, stained glass, and a bright white facade that stands out against the coast. The interior is cool, quiet, and considerably larger than the exterior suggests. Services are held daily and are open to visitors.
The basilica is most atmospheric at dawn, when it catches the early light off the sea. The surrounding Mylapore neighbourhood is one of Chennai's oldest and most interesting areas.