One way of getting here, The Concave, is through conflagration of your Soul. Not a nice way to arrive, but at least you'll have the benefit of a guide, unlike most others.
While walking through the mountains, emerging from several small crevasse near you and begin attacking the party member with the most exposed skin. The Beez are creatures the size of a fist, with minimal stats but high agility. There is ten or more beez. Their sting causes a immediate loss of hitpoints.