Bhairav is a fierce manifestation of Lord Shiva, and Kal Bhairava is the most important among the eight Bhairavas. If ancient scriptures are to be believed, Kal Bhairav temple is said to be related with the Tantra cult, a secret religious sect who thrived upon black magic.
There is a Shivalinga in this temple which during Mahashivratri attracts thousands of visitors to this religious site.