Red Caverns

The Red Caverns were the realm of Lord Dorgar Stoenbrow.

Speculation
These caverns could be located in or around the Alterac Mountains, or somewhere else in Azeroth. Nothing is known about them except that Stoenbrow ruled as lord of the caverns at his death in the Alterac Mountains. They may have been inhabited by the Scarlet Crusade for a time, since Stoenbrow was a member.