- This page is about the physical Underrealm. For other uses, please see Underrealm (disambiguation)
A vast network of caves stretching beneath the surface of Achaea, the Underrealm (not to be confused with the Underworld) is the racial home of such creatures as hobgoblins, goblins, ogres, horkvals, and even the dreaded Tsol'teth. Known in the Tsol'teth tongue as "Anzari-tarin," which means "World of Darkness,". The Underrealm was rediscovered in the 8th century with the help of Parni deSangre in the second Black Wave. Its winding tunnels open into vast regions of darkness, deep shafts, and subterranean valleys, including geographic features such as the desolate Raia'dalam, treacherous Haila'ele, and the mysterious Mainad'harbain. The principal known way into the Underrealm is through a secret archway in the Tsol'teth overland fortress in Pash Valley. Its magical blood-barrier once barred entry against anyone not of Tsol'teth blood, resulting in death for all others, although this effect was nullified after the raising of the underrealm barrier. An alternative is by permission of the Tsol'teth via constructed portals for the convenience of guests such as occurred during the Year 800 championship games.