This great, jumbled mass of granite peaks formed the western march of the Bleak Mountains. Over the centuries, the Fire Tundra had made inroads into the western and southern foothills of the Aeglir Arvethed (S. "Unending Peaks"); but travelers could not expect to find respite among these dreadful peaks—the Aeglir Arvethed were just as drear and lifeless as their forbidding parent range, and the dangers of wind and flooding were equally present. Dwarves had attempted to establish mining colonies in these mountains late in the Second Age, but the mines proved too difficult and costly to maintain for the meager mineral wealth they yielded. The abandoned mines soon thereafter became heavily infested with Trolls from neighboring Torogmar. It was rumored that somewhere near the center of the Aeglir Arvethed ran large, labyrinthine caverns that reached down into the Underdeeps.