Mugician's Arch was a location in the OverWorld.
The Mugician's Arch was located near Ravanaugh Ridge. It was destroyed by a player named Simon alongside his friends. No other players knew about the location so the only scans of the location were in their hands, though it's possible that when Tom Majors and his friends caught the rouge player that the Codemasters gave a scan to Tom and his friends as a reward for their help.
It appeared to be an arch made of rock with several OverWorld Mugicians "swimming" in and out of the arch.
In this location, creatures lose any mugicians that they have.