The Cwm Porth, or "river cavern," a mile below Ystradfellte, is the first of the Mellte's marked eccentricities. The combination of rocks and water and wood, with the added element of danger in exploring this rugged, echo-haunted perforation in the cliff, are attractive in the extreme to the able-bodied traveller. Mellte, in time of flood, carries a deal of amber-tinted water in its rocky bed, and Cwm Porth is not in the hands of a company who charge for admittance, and guarantee smoothed paths, and ropes and handrails where there is a risk of broken limbs. This, indeed, is just the best of the Mellte: you feel as if you are on virgin soil while scrambling at a venture in its steep woods, now on the edge of the roaring little stream fifty feet sheer above a waterfall, and now midway in the river itself, perched on a rock, with vistas of boisterous water up and down, and the river's banks, wooded to the sky-line, hundreds of feet on either hand, at an angle of forty-five or fifty degrees. The writer, on one memorable September afternoon, was for hours alone in these woods, passing from waterfall to waterfall, more by instinct than sure guidance, with the gold and bronze and crimson of foliage constantly betwixt him and the blue autumnal sky; nor did he see sign of other human being than himself, nor more than one white farmstead, when he climbed above the topmost trees and returned to the bleak and bare uplands beyond. The squirrels ran from bough to bough, the birds chirped in the infrequent grassy glades, where the sunlight made a bright spot in the midst of this dense, damp shade, and the waters filled the glen with their clamour. In all England there is nothing of its kind so admirable as the seclusion and beauty of this gorge of the Mellte, with its tributary, the Hepste, to the east. Categorically, the chief waterfalls may be mentioned thus: the Clun Gwyn Falls--Upper, Middle, and Lower--and the two Falls of the Hepste. One cannot describe such things; each of these five has such individuality and beauty that on seeing it you prefer it to the others. Their framing is perfect. Even the heron that gathers up its long legs and whips across the stream out of your way is not wanted to complete your satisfaction in such pictures. Yet in a three miles' flight a crow would reach coal mines and swart heaps of such refuse as you would not dream could lie within scores of miles of these divine solitudes.