They are evil : during a war, they usually put some pieces of fire around the castle until it is only possible to walk there by knowing the position of them and avoiding them. Otherwise, the whole place really is a deadly trap. At first it looks like a natural thing with no danger at all. Even no wall or human construction at all. It simply disappeared because it has been set one fire one day for some reason and came back to normal after a few years, nowdays it comes bad is a deadly trap.