Thought to be one of the oldest temples on the subcontinent, Thirunelly Temple huddles beneath the Brahmagiri Hills 15km southwest of Tholpetty. Non-Hindus cannot enter the temple itself, but it’s worth visiting for the otherworldly cocktail of ancient and intricate pillars backed by mountain views. Follow the path uphill behind the temple to the stream known as Papanasini, where Hindus believe you can wash away all your sins; a trail branches off halfway up to an ancient Shiva shrine.
Buses run to Thirunelly from Mananthavadi (₹35, 1½ hours).