In the Nilgiris' foothills, the newly enlarged 765-sq-km Mudumalai Tiger Reserve is like a classical Indian landscape painting given life: thin, spindly trees and light-slotted leaves conceal spotted chital deer and grunting wild boar. Also here are over 60 tigers, giving Mudumalai one of India's highest tiger population densities (though you'd be lucky to see one). Overall the reserve is Tamil Nadu's top wildlife-spotting place. You're most likely to see deer, peacocks, wild boar, langurs, jackals, Malabar giant squirrels, wild elephants (the park has several hundred) and gaur (Indian bison).
Mudumalai is one important link in an unbroken chain of wildlife sanctuaries known as the Nilgiri Biosphere Reserve, which spans parts of Kerala, Karnataka and Tamil Nadu, and is home to approximately 585 tigers – the world's single largest tiger population.
Mudumalai sometimes closes due to fire risk in April, May or June. Rainy July and August are the least favourable months for visiting.