The Palani Hills around Kodaikanal offer serious trekking for those willing to arrange permits and guides. The hills are part of the Western Ghats, a biodiversity hotspot, and the higher elevations hold shola forest and grassland that are home to Nilgiri tahr, gaur, sambar, and numerous endemic bird species.
The most accessible route is the trail to Perumal Peak (2,460 m), the highest point in the Palani Hills, about 15 km from Kodaikanal. Longer routes into the interior require a permit from the Tamil Nadu Forest Department and must be done with a registered guide. The best trekking season is from October to March — the post-monsoon months, when the forest is lush and the air is clear. Avoid April and May, when the hills are crowded with pilgrims heading to the Palani Murugan temple far below.