This is a Cave of Pinnaku Siddhar. The Cave temple is located behind the Arulmigu Chennimalai Murugan Temple, beyond the Valli temple.
There is a place to sit and meditate. You can go into meditative states here effortlessly.
How to get there
It is located 4.4 kms West of Chennimalai bus stand, on top of Chennimalai Hill.