Ashen Forts

The Ashen Forts are nine fortress-like structures in the land of Gezza, built atop active volcanos and constructed from strange black stone, which shows no trace of human hands and, in fact, seems to be made from solid rock, as if carved out or somehow fused together. Of the nine forts, only 3 are actively inhabited, with Gezkari settlements built inside and around them. Below these forts are said to be mines and forges where the Gezkari are able to produce wondrous metals with shining folds and many other artifacts, some said to possess magical powers. 
It is yet unknown how ancient these forts are, who actually built them, or even how they could have done so. Hathay Delacour listed the Forts as one of the Nine Wonders of the World. He writes, however, that he was never allowed inside. The famed scholar Tycho Nastoris was also denied access to the forts by the Gezkari, though he seemed to gather from the locals, that there was much more than mines in the deep.