Vandiperiyar Sree Dharmasastha temple is located on the Vandiperiyar - Thengakal Road in Idukki district, Kerala. The shrine is dedicated to Ayyappa or Dharma Shasta and is on the banks of Periyar River. The shrine observes the annual Karkidaka Vavu Bali and Pitru Tarpanam on the Vavu or Amavasya day in Karkidakam month. Hundreds of people arrive at shrine and offer various rituals to ancestors. Special arrangements are made by temple management for Bali Tharpanam on the occasion.
As per local history, a sixteen year old boy, believed to be Ayyappa, helped Manavikrama Pandyan in his fight against dacoits. The temple is located in the exact spot where Ayyappa appeared.
Vandiperiyar Sree Dharmashasta Temple, which is thousands of years old, is built in the Tamil style of architecture. The upa devatas worshipped in the temple are Subramanya, Bhagavathy and Ganesha.
There is a miraculous stone in the temple complex. If anyone disturbs the sanctity of the stone, a boar is said to attack them.
The temple is surrounded by tea estates and thick forest.
The annual Mandala Makaravilakku season attracts thousands of Ayyappa devotees to the temple.