Gap Chasm, also referred to as the Gap, is a deep chasm which crosses the length of central Xanth.
The Gap is notable for it's rule in keeping quarreling factions divided and invaders from easily reaching southern Xanth. It is protected by the Gap Dragon, who lives there and works to keep as many people from crossing as possible. On the North side of the Gap is Gap Village. There is also a Gap Goblin tribe too.
There is an ignorance spell cast on Gap Chasm. Those in the vicinity of the Gap are aware of it's existance. Those who leave the area around the Gap forget about it's existance. This is why the Gap is rarely seen on maps of Xanth.