The Bluestone Hills which partially are part of the 7AN get their name from the blue stones that can be found and mined in the hills. Bluestones have magical properties and extremely rare and valuable.
In 5654, before the Second Demon War, there was a find of Bluestones here, and a lot of people headed there in hope of salvation and riches. Small mining towns popped up here and there, with everybody and their dog looking for the magical but elusive blue stones. But most are disappointed. Some gems were however found, making their owners rich beyond their wildest dreams, or dead.
Aside from the mining towns, the hills crawl with evil humanoids and cultists.