Tiruparankundram is one of the six abodes of Lord Murugan, carved into the side of a great granite hill 8 kilometres south of Madurai. The temple is partly rock-cut and partly built over centuries, with sculptures from the Pandya, Nayak and Vijayanagara periods overlapping in the same dim halls.
Half a day is enough — the climb up the back of the hill behind the temple is also worth doing for the view across the plain back to Madurai. Avoid Tuesdays and full-moon evenings when crowds peak.