When a person has occasion to traverse these narrow and fatiguing roads, it is necessary for him to keep a good look-out, lest he should clash with some rider or cargo-beast coming in the opposite direction; for there are places where it would be utterly impossible to pass two a-breast; and there would be no small danger, on meeting an impatient animal or careless horseman, that either party would be hurled over the brink, and consigned to the condors and eaglets that nestle on the cliffs and in the dark chasms of the crags. Such dangerous passes are at some places so contracted that the stirrup of the muleteer is seen to overhang the foaming stream, or project beyond the verge of the boldest precipice; and every now and then they are made more formidable by abrupt angles and insecure breast-work without parapets, hastily constructed when the rush of a sudden torrent from the hollow of a hill, or large stones rolling from the heights, have cleft the way so as to render it for a time impassable. There are also many cuestas or rapid steeps, with here and there flights of steps, roughly cut in the hard rock. By the way-side, in tedious cuestas of several leagues in extent, recesses are, in numerous instances, worked out on the higher side of the road, which serve for the passengers to draw up while those from an opposite direction are allowed to pass on, or where muleteers stop their cattle to adjust their cargoes and tighten their lazos. But when a rock or shoulder of a cliff juts out from the road towards the lower or precipice side, leaving more or less room for a resting-place, then the little flat space is coarsely walled in with large fragments of rock and such smaller stones as may be at hand, giving the idea of a rude but commanding fortress.