Khalimgrad is an uberlevel, entered from a portal opened by using Dark Portal after killing Izual in the Plains of Despair. It is predominantly inhabited by Ethereals, whose death reduces nearby enemies' resistances, breaking the invulnerability of the pre-placed Zakarum's Avatar minibosses in the process. Despite the presence of two super unique monsters Imperius and Malthael, the ubercharm Zakarum's Ear is not dropped by them, but rather by the Zakarum's Avatars; instead, killing one of the super uniques allows Dark Portal to be used again, this time to open the way to the Diamond Gates.
Heaven. Nirvana. Celestia. Call it what you will. Home of the heavenly host, which almost destroyed the taint on creation that is the mortal plane twice and allowed it to get overrun by the forces of Hell. Far from being the beings of love they are believed to be by the common folk, the angels of the High Heavens present a clear and present danger to Sanctuary. It may be better to strike first.