Netherspace is a region that is part of - but somehow exists beyond - the walls of Karazhan, and is the location of the tower's new master, Prince Malchezaar. The top of the tower can be seen from the other side of this "room", but upon going out onto the Master's Terrace, Netherspace is not visible. In Netherspace, there are several easter eggs if you look into it like a Skeletal Gryphon and a sleeping Nightbane.