Puranic texts suggest Ishan, a form of Shiva, dug the well to cool Vishveshvara (Vishwanath) with water.
This was a time when there was no water on earth.
The water that came out of this well is considered the liquid form of gyan (wisdom).
Scriptures say Gyanvapi has the power to drive away evil spirits and cleanse sins off devotees.
The well was dug in Kashi long before the existence of Ganga.
Other names of Gyanvapi well are the Shivatirtha, Gyanodatirtha, Tarakatirtha and Mokshatirtha.
The Gyanvapi is within the boundary of the Kashi Vishwanath Corridor.
The Vishwanath temple was partially destroyed during the rule of the Sharqi kings of Jaunpur (1436-1458 CE) and was completely demolished by Sikandar Lodhi in 1490.