National Institute of Siddha is located at the foot hills of Pachamalai with serene green atmosphere in Tambaram sanatorium. A well built Green house with 250 medicinal plants are grown and maintained for the purpose of identification, conservation and hospital utility. An exclusive Medicinal Garden of 1000 sq.m area is established by the side of the In-Patient hospital. Around 150 medicinal trees and shrubs are planted in the garden for academic purpose. Around 90 medicinal trees are planted in and around the campus. Post graduate Siddha students of all disciplines and academic researchers from other institutions are able to learn hundreds of plant species under one roof. The functions of Herbal garden and Green house are, Introduction, multiplication, acclimatization, assessment and documentation of medicinal plant species from various sources. Rare and Endangered medicinal plant species are also conserved in the herbal house and garden.