Very deep in this enchanted land of green hills in which I live, lies a still and quiet valley. No road runs along it; but a stream with many curves and loops, deep-set in hazels and alders, moves brimming down. There is no house to be seen; nothing but pastures and little woods which clothe the hill-sides on either hand. In one of these fields, not far from the stream, lies a secluded spot that I visit duly from time to time. It is hard enough to find the place; and I have sometimes directed strangers to it, who have returned without discovering it. Some twenty yards away from the stream, with a ring of low alders growing round it, there is a pool; not like any other pool I know. The basin in which it lies is roughly circular, some ten feet across. I suppose it is four or five feet deep. From the centre of the pool rises an even gush of very pure water, with a certain hue of green, like a faintly-tinted gem. The water in its flow makes a perpetual dimpling on the surface; I have never known it to fail even in the longest droughts; and in sharp frosty days there hangs a little smoke above it, for the water is of a noticeable warmth. This spring is strongly impregnated with iron, so strongly that it has a sharp and medical taste; from what secret bed of metal it comes I do not know, but it must be a bed of great extent, for, though the spring runs thus, day by day and year by year, feeding its waters with the bitter mineral over which it passes, it never loses its tinge; and the oldest tradition of the place is that it was even so centuries ago. All the rest of the pool is full of strange billowy cloudlike growths, like cotton-wool or clotted honey, all reddened with the iron of the spring; for it rusts on thus coming to the air. But the orifice you can always see, and that is of a dark blueness; out of which the pure green water rises among the vaporous and filmy folds, runs away briskly out of the pool in a little channel among alders, all stained with the same orange tints, and falls into the greater stream at a loop, tinging its waters for a mile. It is said to have strange health-giving qualities; and the water is drunk beneath the moon by old country folk for wasting and weakening complaints. Its strength and potency have no enmity to animal life, for the water-voles burrow in the banks and plunge with a splash in the stream; but it seems that no vegetable thing can grow within it, for the pool and channel are always free of weeds.