Kolramas is a fallen necropolis located south of the Altar of Har'koa in Zul'Drak. The Drakkari brought down Kolramas, but not all of the Scourge within died. Now the Hath'ar undead nerubians are coming out and Hath'ar Necromagi are raising fallen Argent Crusade soldiers. Malas the Corrupter leads the Scourge forces here.
Kolramas had a huge shipment of saronite. This is also one of the places where the player first encounters the substance. The quests in Dragonblight deal with it, but it is during where its potential is revealed.