Demonskar

This terrible crater in the middle of the trackless jungle was once the site of a Spell Weaver city. When an attempt to build a structure to allow planar transport on a massive scale failed, the entire city vanished in a terrific explosion of abyssal energies. The place has since come to be known as the Demonskar, if only for the fact that it is infested with demons trapped here when that fateful explosion tore them out of the Abyss and stranded them on the Material Plane.