Abridged History of the 10th Age
Hilmirhol is the seat of the Rìkonungr, the High King of Dwarves. Hilmirhol is the most opulent of all dwarf cities; when approaching it, most men would assume that the massive constructs of rock visible outside the mountains comprised its bulk. Indeed, it looks as large and beautiful as any human settlement. Yet the facades and galleries beneath the mountain are the true city, nearly five times the size of the city spilling down the mountain face. The great clan-halls are all located below ground and are veritable fortresses to themselves.
Hilmirhol has been the center of Dwarvish culture since the drowning of Harnholme. Before that time it was little more than a deep military outpost; however, since it was the strongest fortress not to be shaken by the cataclysm many of the leading clans of Mountainholme fled there. While Heimsgar∂ is undoubtedly the most wealthy and beautiful of holds, Hilmirhol is the more populous, and more powerful.