As there is already a question about Jnanavapi, where answers are quoting from Skanda Purana, Kashi Khanda to give the details information about Jnanavapi. It says:
- Īśāna who was identical with Rudra in a terrible physical frame, dug up a deep pit with terrific speed by means of his trident. The place was to the south of Viśveśa and very near him.
That means Visvesvara Linga was already present there. So, I would like to know that what were the dimensions of that Linga? Is there any scripture talk about it? Can we also know the dimensions based on Nandi statue present there?