Hellmouth

A Hellmouth is a fictional metaphysical phenomenon featured in the WB Network/UPN television series Buffy the Vampire Slayer. It serves a focal plot device for the series, as well as the explanation as to why so many supernatural creatures exist in the world.

A Hellmouth is a mystical aperture that bridges the dimensions between reality and the realms of Hell. A confluence of mystical energy, it is an ephemeral portal of great power. Demons and vampires are frequently drawn to it, and more than one nefarious individual has attempted to take control of a Hellmouth. The most famous Hellmouth is the one located beneath Sunnydale High School in Sunnydale, California. This Hellmouth was destroyed however by the next generation of Slayers as well as a vampire "Champion" named Spike. Watcher Rupert Giles informed them only moments later that another such Hellmouth existed in Cleveland.