South India has many places that cater to the nature-lover’s soul. As you have asked for ‘natural’ places, I’ll assume that you would not want to visit the umpteen historical sites dotted all over south India. Besides those, here are my top recommendations…
Top Slip, Coimbatore, Tamil Nadu
Topslip is located at 2554 Feet (774 Meter) above sea level on the Anamalai mountain range. It is popularly known as Anamalai Hills. It is a small place in Anaimalai Tiger Reserve and Wildlife Sanctuary that lies in the Coimbatore District of Tamil Nadu at the southern part of the Nilgiri Biosphere Reserve.
Topslip is about 37 km from Pollachi, the nearest town, and 9 km from the village of Sethumadai.
WAYANAD, KERALA
- Kuruva Island, Wayanad
Kuruvadweep (Kuruva Island) is a 950-acre (3.8 km2) protected river delta on the Kabini River in the Wayanad district,Kerala, India.This island of dense and evergreen forest is uninhabited and hence a home to rare kinds of flora and fauna: uncommon species of birds, orchids and herbs
- Edakkal Caves, Wayanad
Reachable after a 1km uphill trudge through a coffee estate, Edakkal Cave is one of India's most important prehistoric rock shelters. It is said to be one of the earliest centres of human habitation.
- Hridaya Saras or Heart Lake, Wayanad
This is a beautiful heart shaped lake located on the way to the top of the Chembra Peak, the highest peak in Wayanad.
Wayanad has a lot of beautiful places you could visit. Here is a helpful link to know more →45 Places to Visit in Wayanad | Tourist Places, Sightseeing, Attractions in Wayanad | HolidayIQ.com
Gavi, Pathanamthitta, Kerala
Gavi, an island decorated by evergreen forests is 28 km south west of Vandiperiyar, 14 km from Kumily, near Thekkady.
Munnar, Idukki, Kerala
Munnar is a town and hill station located in the Idukki district of the southwestern Indian state of Kerala. Munnar is situated at around 1,600 metres (5,200 ft) above sea level, in the Western Ghats range of mountains. It is just a two-hour drive from my home is my personal favorite haunt. The place never fails to mesmerize me with its beauty.
Besides these, there are also the popular holiday spots of Kodaikanal, Ooty, Yercaud, etc. But if you’re looking for a place to just unwind and relax, then these are THE places for you.