It's Europe, of course, although with a few key differences such as the English Channel being filled in. There's also that Mordor-like mountain ring in Ukraine, which is a bit east of the real-life Carpathian Mountains that are usually used to align Middle-Earth and modern Europe:
It's fitting, somehow, that Sauron's domain should end up being the homeland of Count Dracula.
I also notice, on the Forgotten Ruin map, that the Egyptian area is labeled "Kingdom of Sut", which to me sounds very much like Set, the patron serpent-deity of the Stygians of Robert E. Howard's Hyborian Age. Handily, they also correspond roughly with Egypt: