Kodaikanal
Similar to Ooty, even Kodaikanal is a one of the famous Hill Stations of Tamil Nadu surrounded by Western Ghats. You can easily spend 3-4 days here as you have places like Vattakanal, Kodhaikanal Lake, Bryant Lake, Pillar Rocks, Dolphin's Nose, etc. Even Kodaikanal could be an overnight journey from most of the southern Indian cities.