Kaal Bhairav Temple
Long time back several great sages sitting a top of Sumeru Parbat (Mountain) desired to know from lord Brahmaas to who was indestructible & supreme. Lord Brahma proclaimed himselfto be that superior person. On hearing this Yagyeshwar (Lord Vishnu) reprimanded Lord Brahma for his hasty & audacious utterances.
Both of them went to four Vedas to asked the same question. Rig Veda replied that the omnipotent deity who controls all liivng beings, named Rudra is supreme. Yajur Veda replied that He, whom we worship through various Yagnas (Yagam) and other such rigorous rituals, is none other than Shiva, who is supreme. Sam Veda stated that the respected figure who is worshipped by various Yogis and that person who controls the entire world is none other than Trayambakam. Finally Artha Veda said, all human beings can see the Lord through Bhakti Marg and such a deity who can remove all the worries of human being is indeed Shankar. In a nut shell, all the four Vedas proclaimed that Lord Shiva the ultimate being.
Both Lord Brahma and Yagya Narayan started laughing in disbelief. Shortly, Lord Shiva appeared as a powerful divine light in the midst. Lord Brahma stared at that Being furiously with his fifth head. Lord Shiva immediately created one living being & stated that he (that new being) will be king of Kaal and will be known as Kaal Bhairav. Lord Shiva further stated Kaal Bhairav will always be in Kashi, removing all sins of the devotees and therefore, he will be known as Paap Bhakshak.
Meanwhile, Lord Brahma's fifth head was still burning with fury and Kaal Bhairav plucked that head (just as we pluck flowers from the garden). Immediately all the people present there started singing praises of Lord Shiva. Lord Shiva directed Bhairav to go around various places but Brahma Hatya Dosh (affliction on account of hurting a Brahmin) will always follow him. Lord Shiva created a dangerous & feirce looking female figure named Brahma Hatya and asked her to follow Kaal Bhairav wherever he went.
Kaal Bhairav, with Brahma's head in his hand, started going around various places in the world, took bathe in the various Teerths, worshipped various Lords, nevertheless saw the Brahma Hatya was following him all along. He could not get rid of that affliction.
Finally, Kall Bhairav reached the Moksha Puri, Kashi. The moment Kaal Bhairav entered Kashi, Brahma Hatya started shouting screaming and finally disappeared into the netherworld. The head of Brahma, (Kapaal) fell at a place which was called Kapal Mochan and there was a Teerth which was later called Kapal Mochan Teerth. Then onward Kaal Bhairav stationed himself permanentely in Kashi, giving shelter to all bis devotees. Those living in or visiting Kashi, must worship Kaal Bhairav and he grants protection to all his devotees.
Ashtami day (eighth day after poornima) in the month of Margashirsha is an important day for worshipping Kaal Bhairav. Besides, Sundays, Tuesdays, Ashtami and Chaturdashi days are very important for worshipping Kaal Bhairav. A person who circumabulates Lord Kaal Bhairav eight times will be absolved of all the sins committed by him. A devotee who worships Kaal Bhairav for six months will attend all types of Siddhi (Kashi Khand Chapter 31).
Old timers in Kashi believe whenever residents of Kashi leave the city for short journeys, they worship Kaal Bhairav (taking his permission) and on return back to Kashi, they again worship Kaal Bhairav.