Here is my one more finding in ooty which is must visit but with a disclaimer. this is not free for casual visit as it is heavily guarded by forest dept. You need to gain access through your rapport with guard or obtain NOC from head office in ooty. It takes you to the top most dam in deep woods of nilgiris where you wont find any human activities for about 30kms frm last house in thaishola tea estate.
Once u r in ooty, keep a day to visit this dam and be back safely before it gets dark. take a route towards emerald lake and reach manjur from which you keep getting deeper into thick jungle, which is same as we see in infamous wrong turn movie. be ready to be surprised by sambar deer that can be spotted at any sharp turns u get across. this will be as closer as u get into undisturbed jungle.
Disclaimer: Do respect the nature and contribute your bit by enjoying the nature without disturbing it much. here are some glimpses while I will share my dashcam video tomorrow to give u fair idea on this hidden heaven.