Many are the legends that animate the Beacons. Enough if we believe with certain of the bards that it was here, on Pen-y-Fan, that Arthur called his chivalry together, and initiated the Order of the Knights of the Round Table. In the land of the Red Dragon, centuries ago, there could be no higher dignity than to be associated with him who was to appear for the glory of Britain: "the lamp in darkness":-- "In forest, mountain, and in camp, Before them moved the Burning Lamp; In blackest night its quenchless rays Beckoned them on to glorious days." [Illustration: _Photo: F. Bedford, by permission of Catherall & Pritchard, Chester._ LLANDAFF CATHEDRAL: THE NAVE AND CHOIR (_p. 164_).] Having clambered, not without considerable exertion, to Pen-y-Fan, the traveller, if he feels thirsty, has but to turn his back to the north, face the distant smoke clouds above the hills of Merthyr and Rhymney, and walk a few yards down the western slope of the mountain. Here are two ice-cold springs, the parents of baby rivulets. Below you see how briskly these rivulets broaden and unitedly carry the pure water to the south. This is, in fact, one of the two main sources of the /Taff/. The other also is on the Beacons. The two streams, Taff Fawr and Taff Fechan (the "Great" and "Little" Taff), run parallel, in respective glens, among heather and rocks, for eight or ten miles, to join just above Merthyr. Pollution of all kinds comes to the stream as soon as it is thus fully entitled to be called the Taff. Even before Merthyr is reached, Taff Fawr has learnt something of the pains and penalties of an industrial district. Ere it has run five miles from its source, it falls into the hands of the Cardiff Corporation. Its valley is here a characteristic mountain glen, with heathery solitudes on either side, and little clefts among the heather by which nameless affluents bring their pure tribute to the main stream. Houses there are none. But of a sudden, in all this loneliness, you come to a huge dam built and building across the valley from east to west, and beyond you perceive the goodly lake of which the rising dam is to be the mighty northern boundary. [Illustration: RIVERS OF SOUTH WALES.]