Lord Shiva was overwhelmed by Vashishtha's sincerity and devotion and granted accordingly. He appeared as Kedareshwar in Kashi and told Vashishtha that worshiping Kedareshwar in Kashi would yield seven times more merit than worshiping Kedareshwar in the Himalayas (Kashi Khanda, Chapter 77).
Gauri Kund, Hans Tirtha and Mansarovar Tirtha are mentioned in the Kashi Khand in the context of Kedareshwar, but now only Gauri Kund is left. Mansarovar and Hans Teerth have dried up.People keep a fast (Vrat) on Shukla Paksha Chaturdashi in Chaitra month (March- April) and break their fast after worshiping Kedareshwar on the next full moon day.
It is stated in Kashi Khand where Vashishtha used to worship Lord Kedareshwar on Chaitra Purnima day (as mentioned in above para). Kashi is divided into three sections, Omkar Khand, Vishweshwar Khand and Kedar Khand. It is believed that one who dies in Kashi attains salvation.
Going one step further, if death occurs in the Kedarkhand ruled area, he attains salvation immediately, whereas in the other two classes, he has to face some kind of suffering.There are twelve Jyotirlingas on all India basis and there are twelve important Shiva Lingas in Kashi which represent the above mentioned twelve Jyotirlingas.
Kedareshwar (Varanasi) is worshiped as Kedareshwar Jyotirlinga (Uttarakhand). Kedareshwar is a Shiva temple in the Himalayas which is one of the twelve Jyotirlingas. According to Kashi Khand, a gentleman had performed the Upanayana ceremony of his son named Vashishtha in Ujjain. The child, Vashishtha, was very religious and used to perform all the pujas including Linga Puja etc.
He regularly visited the Kedareshwar temple in the Himalayas with his guru and worshiped Lord Kedareshwar.Once, on his way to Kedareshwar, the Guru unfortunately died and since he had always done good deeds, he found a place for himself on Mount Kailash.
Vashishtha, who was then 12 years old, learned that one who visits Kedareshwar is blessed with all virtues. After this he settled in Kashi. But on all Chaitra month full moon days (March 20-April 21), Vashishtha (who remained celibate) used to go to the Himalayas to have darshan of Kedareshwar Linga and this process continued for 61 years.
But due to old age he could not go out and he started praying to Lord Shiva in Kashi. Lord Shiva blessed him with a wish and Vashishtha requested that Lord Shiva please appear as Kedareshwar in Kashi itself.