This is a consecrated linga of Shri Manikarnikeshwar Mahadev.
There is a place to sit and meditate. You can go into meditative states here effortlessly.
How to Get there
The temple is located at Ghasi Tola; north of Manikarnika Kund.
Map:
https://goo.gl/maps/m7xCTzpFdD6kcGq47
About Shri Manikarnikeshwar Mahadev Temple
According to Lord Vishnu, devotees who take bath in Manikarnika and worship Manikarnikeshwar will not see mother’s womb again (meaning – there will be no rebirth).
The linga is located underground, devotees can go all the way down to have a darshan of Shri Manikarnikeshwar Mahadev.
Read More:
Shiv Lings of Kashi by Lalitha V