She and Allan by H. Rider Haggard

We won out of the reeds at last, for which I fervently thanked God, since to have crossed that endless marsh unguided, with the loss of only one man, seemed little less than miraculous. We emerged from them late in the afternoon and being wearied out, stopped for a while to rest and eat of the flesh of a buck that I had been fortunate enough to shoot upon their fringe. Then we pushed forward up the slope, proposing to camp for the night on the crest of it a mile or so away where I thought we should escape from the deadly mist in which we had been enveloped for so long, and obtain a clear view of the country ahead.

Following the bank of a stream which here ran down into the marsh, we came at length to this crest just as the sun was sinking. Below us lay a deep valley, a fold, as it were, in the skin of the mountain, well but not densely bushed. The woods of this valley climbed up the mountain flank for some distance above it and then gave way to grassy slopes that ended in steep sides of rock, which were crowned by a black and frowning precipice of unknown height.