The Annamalai Reforestation Society (ARS) has been actively involved in reforesting the Arunachala Hill in Thiruvannamalai since 1988.  The ARS is the earliest society at Thiruvannamalai established with the primary aim of reforesting the sacred Arunachala Hill and the surrounds.

The main objectives of the society:
To work for the afforestation and conservation of the Arunachala hill
To create and maintain fire lines on the hill to prevent fires from spreading and to aid in fire fighting
To generate awareness of our natural environment, its problems of soil erosion, loss of genetic diversity, depletion of water resources etc.
To encourage participation in the regeneration and protection of animal, bird and plant life on the hill and the surrounding areas
These are achieved through awareness campaigns, educational activities and employment opportunities generated through activities on the hill and the organic farm. ARS is responsible for the regeneration that the forest has undergone over the last quarter century and more.