The portal to this dungeon opens for a brief period inside the Monouga Feeding Pits dungeon by first giving a Monouga Laboratory Portal Attunement Gem to the 150 Bell (north at the first intersection), then ringing the bell. Creatures respawn quickly (2–3 minutes) and are the spawns are thick. Unless you have a large party it is probably easier to run rather than fight. There are no surface portals in this dungeon, you must run back if you die (you can get multiple gems by talking to the NPC in Cragstone several times, a new gem is needed each time to reopen the portal).