On a journey on foot across the countryside with some other men. Post apocalyptic feel. We came across some rocky terrain, and there was a sudden dip to this ravine, surrounded by cliffs. There was the wreckage of a large crashed helicopter – lying on its side – but there was something more at the bottom of the ravine. If you peered over the edge of the ravine you could see some sort of structure about four floors down. It might have been another craft that had crashed, or a military shelter or base that had been abandoned. The ravine was steep – unnaturally so, so that the walls may have actually curved almost in the fashion of cliffs in cartoons.