Gnomeregan is a dungeon whose entrance is located in Dun Morogh in the World of Warcraft game. The level range for the normal dungeon is 29-38. The only achievements you can get in this dungeon are the ones for completing. There are no achievements awards for individual boss encounters for making him to do something. Classic raids and dungeons only had one mode and that was normal. Heroic level versions of the dungeon started in the Wrath of the Lich King expansion. Starting in Cataclysm and onwards, Heroic level dungeons were introduced for the highest level.The main anagonist race in this dungeon are Gnome. The dungeon contains 7 bosses. The end boss of Gnomeregan is Mekgineer Thermaplugg.
Gnomeregan is the underground home of Gnomes who were kicked out in a coup by one of their senior leaders, Mekgineer Thermaplugg. The Gnomes have moved in with the Dwarves of Ironforge. This dungeon sees you trying to reclaim the dungeon however Gnomes don't move back in after its been cleaned out.
The main antagonists in this dungeon are leper gnomes, troggs and various elementals such as water and the odd Ooze. There was an one off special event in September 2010 where you assisted the gnome king to reclaim the home which gave the impression that gnomes might be moving back but it wasn't to be, the gnomes were kept out. The achievement became known as Operation:Gnomeregan. There was an equivalent event achievement to be done for the Horde.
The location of the entrance to Gnomeregan is located on the western side of Dun Morogh, to the north of the area where gnomes and dwarves start their adventures. If you are a low level alt, its best to avoid the area as it is all guarded by enemies that find it easy to kill you.