The Dee has finally emerged from the mountainous country when it flows, with many a sharp bend, and long, glittering loop, between the grounds of Chirk Castle and of Wynnstay. It is shortly to become a river that is English on the one side and Welsh on the other, and already, except in the distance, we have seen the last of the characteristic scenery of North Wales. The Dee now courses through a country of wide plains. Offa's Dyke runs in a straight line through the grounds of Chirk Castle, almost to the point at which the stream is crossed by the railway viaduct. Watt's Dyke commences on the other side of the Dee, a little lower down, and proceeds through the grounds of Wynnstay, past Ruabon, in the direction of Wrexham. What may have been the purpose of these ancient fortifications is a question which the antiquaries have so far failed to answer in any way that is final and conclusive. Thomas Churchyard has an explanation which is as good as any that has since been offered. He says-- "There is famous thing Cal'de Offa's Dyke, that reacheth far in length; All kind of ware the Danes might thither bring; It was free ground, and cal'de the Britaine's strength; Wat's Dyke likewise about the same was set Between which two both Danes and Britaines met, And trafficke still." At these Dykes, too, it would appear, the exchange of prisoners was generally effected. In their origin, no doubt, they were defensive works, as well as lines of demarcation. [Illustration: THE ROODEE, CHESTER (_p. 239_).] After its junction with the Ceiriog, the Dee divides Denbighshire and Shropshire for some two or three miles. Soon afterwards it again becomes wholly Welsh for a brief while, and forms the boundary between Denbighshire and Flint. This is after we have passed Ruabon, and the great Welsh coalfield. Here is Overton Churchyard, one of those "seven wonders of Wales" whose title to fame is so often inexplicable. At this place there is less to wonder at in the churchyard itself than in the view of the Dee which is presented therefrom, for here it winds, with many curves, through a pleasant valley, interspersed with broad, flat green spaces, woods, and low, rounded hills. Bangor-on-Dee, the chief spawning ground for salmon, is near at hand; and, then, before long, the great tower of Wrexham Church comes in sight, much more of a wonder than either Overton Churchyard or Llangollen Bridge. [Illustration: THE DEE AT CHESTER, FROM THE WALLS (_p. 239_).]