The Mountains are often dormant volcanos, and the biggest of which is Hellish Peak. Lava often runs down the Mountains, making large cliffs in the lava rocks. Underneath the mountians, catacombs run for miles next to lava pits. The mountain range stretches from the Fire Spirit's kingdom to the sea, were the towering rocks drop off.
The Blackwood mountians have large depostits of rubies, which is why Fire Spirits have always lived there. It also shelters the Spirits fromt the sea, which would kill them. They are called the Blackwood mountains because in a big volcanic explosion, all of the trees were burned, and eventually decayed.