Several parts of an ancient wall that once surrounded Chepstow still remain, with the watch-towers complete; and one gate dating from the sixteenth century--the Town Gate--still stands, a curious archway across the principal street, a thoroughfare that slopes steeply down to the Wye. A church of great antiquity is Chepstow Church, built in the days of the Normans, and containing several monuments of unusual interest, with the grave of Henry Marten, one of the signatories of King Charles's death-warrant, who spent many long years as a prisoner in Chepstow Castle. One of the towers of the castle is called Marten's Tower, an unintended commemoration of the Roundhead's imprisonment within its walls. Bidding a final good-bye to towns and tributaries, but still retaining its rugged banks and, in a measure, its stately woods, the Wye makes straight for the sea, where this child of the mountains, after swallowing the largess brought down to it by a score of smaller streams, is itself, in turn, swallowed in the greater flood of the Severn. To the very last, however, the Wye retains its individuality and character--picturesque ever, picturesque to the end. From its fount on Plinlimmon to the end of its course of a hundred and thirty miles, where it gracefully rolls into the broad estuary, it has scarcely ever, even for a mile, been commonplace. /E. W. Sabel./ [Illustration] [Illustration: NEAR THE SOURCE OF THE USK, TALSARN-SIDE.] THE USK. The Black Mountains--Trecastle--The Gaer--Brecon--The Brecknock Beacons--Crickhowell--Abergavenny--Usk--Caerleon and the Arthurian Legend--Christchurch--Newport. The wild and inclement Black Mountains, "Fforest Fawr," between Carmarthenshire and Brecknockshire, collect the first drops that, trickling down the side of the hills, gather volume and strength and in time become rivers that are the delight and pride of a country. Three springs, clear and tiny, away up the dark mountain side, where Talsarn towers to an altitude of more than 2,500 feet, are the fountain-heads of a river that, after an extended course of seven-and-fifty miles in the general shape of a bow, joins the sea at Newport--the /Usk/.[9] Not far away are the sources of many another river--the Tawe and the Neath, to name but two; but of all the streams that are born in this cheerless region the Usk is by far the most important.