Sri Chakrapuri (ஸ்ரீ சக்ரபுரி)- This is the ancient name of Famous Siva Temple Thiru Annamalai (திரு அண்ணாமலை ).It is said Lord Siva himself resides here in the form of a Mountain.Many Mahrishis and Guru's of India had lived there.
In Thiru Annamalai GiriValam (கிரிவலம்) during Full Moon is so Famous.It is said If we go Girivalam continuously our negative karma will begin to decrease.
Scientifically during Full Moon, the Planet Moon will be having its Highest energy.Usually the dieties situated in Hills or beside sea receive high cosmic energy. When a human being goes to this places on this day will recieve high cosmic energy so that his mind will be triggered to make very clear decisions.This helps in overall improvement of a mind and body.
These 2 blogs explain experiences of 2 people .
For scientific explanation please visit the links below