Madumalai Wildlife Reserve
In the foothills of the Nilgiris, this 321-sq-km wildlife reserve is like a classical Indian landscape painting given life, with chital deer, wild boar, gaur (Indian bison), peacocks, langurs, jackals, Malabar giant squirrels and wild elephants concealed between thin, spindly trees and light-slotted leaves. Also here are around 50 tigers, giving Mudumalai one of India's highest tiger population densities – though you'd be incredibly lucky to see one. Overall, Mudumalai is Tamil Nadu's top wildlife-spotting place.
Anamalai Wildlife Reserve
A pristine 950-sq-km reserve of tropical jungle, shola forest and grassland rising to 2400m in the Western Ghats and spilling over into Kerala between Kodaikanal and Coimbatore, Anamalai Tiger Reserve is well off most tourists' radar.
On government-run guided hikes or jungle minibus 'safaris', you might well see elephants, peacocks, spotted deer, lion-tailed macaques, langurs and crocodiles, but other elusive, endangered inhabitants include leopards and around 30 tigers. It's been a designated tiger reserve since 2007.