Nilakkal Mahadeva temple is located at Nilackal on the way to Sabarimala in Goodrical range of Ranni forest division in Pathanamthitta district, Kerala. The shrine is dedicated to Shiva – Mahadeva. The annual Shivratri festival (February or March) is observed in at Nilakkal temple.
The popular belief is that Ayyappa who was on the way to annihilate a demon got the blessings of Shiva, his father, at Nilakkal. Shiva here has two forms one is ferocious and another form benign form blessing his son. It is said that Shiva was ferocious due to the atrocities of the demon but was happy to see his son on the mission to annihilate the demon.
A Shivling is worshipped in a two tier round sanctum sanctorum – vatta sreekovil.
The Upa Devatas worshipped in the temple are Kannimoola Ganapathy and Nandi.
Pilgrims on the way to Sabarimala temple take rest in the temple.
The annual Shivratri festival is observed with Tantric and Vedic rituals. Dhara, mantras, various pushpanjali and other rituals observed during festivals in Shiva temples are held here.
Palliyarackavu Bhagavathy temple is located 300 meters south east of Nilakkal Mahadeva Temple.