There are three warriors at the Summit of Mount Arreat that protect the entrance to the Worldstone Keep. Their names are Korlic, Madawc, and Talic. The three warriors were summoned by The Ancients to go to the summit and protect it, honored as they were they departed to Guard the Worldstone for all eternity. When you reach the summit you must face the three warriors in battle to pass on to the Keep.
While the Barbarian Ancients would have delayed Baal, he received a key from Nihlathak that allowed him to pass. The Worldstone was eventually corrupted by Baal and so destroyed by the Archangel Tyrael.
After the events of Diablo II, Mount Arreat was destroyed by a cataclysmic explosion caused by the destruction of the Worldstone. It is now called Arreat Crater and is located in the Dreadlands, as shown by the map located on the official Diablo III website. It appears that the destruction of the Worldstone had a catastrophic effect on the region.
|Locations in the Diablo Universe|
|Planes||Black Abyss • Burning Hells • High Heavens • Sanctuary • Trag'Oul's Realm • The Void|
|Regions in Sanctuary||Aranoch • Dreadlands • Entsteig • Kehjistan • Khanduras • Mount Arreat • Scosglen • Skovos Isles • Torajan Jungles • Westmarch • Xiansai|
|Towns in Sanctuary||Bastion's Keep • Bramwell • Caldeum • Duncraig • Gea Kul • Harrogath • Hashir • Istani • Ivgorod • Kalinash • Kehjan • Kingsport • Kurast • Lut Gholein • New Tristram (Old Tristram) • Partha • Rogue Encampment • Seram • Staalbreak • Toraja • Tran Athulua • Tulisam • Tur Dulra • Ureh • Urjhani • Viz-jun • Westmarch|
|Other Places||Pandemonium Fortress • Silver City|