The road from Abergavenny to Brecon, bordering the clear and lively Usk in a romantic valley, soon leaves the charming county of Monmouth; but is attended with such a continuance of agreeable scenery as may diminish in a considerable degree the regret of the tourist. Among the verdant accompaniments of the serpentizing river, the rich groves and smiling lawns of Dany Park are conspicuous, swelling above a fertile vale, and backed by a range of wild mountains. Nearly opposite this, in a field to the right of the road and the fifteen mile-stone from Brecon, is a single upright stone, about fourteen feet high, conjectured to be a monument of the druidical ages. CRICKHOWELL, about two miles farther, is an old mean-built town; but, hanging on the steep declivities of a fine hill, and dignified with the picturesque ruin of a castle, it is an interesting object in the approach. The extent of this fragment of antiquity (of obscure origin), sometimes called Alashby Castle, is by no means considerable; the foundation of the keep, seated on a high artificial mound, denotes much original strength, and all the standing walls shew a very remote erection; although a few enrichments of later times may be perceived beneath the thickly-woven ivy. A narrow Gothic bridge crosses the Usk here to the pleasing village of Langottoc, the neighbourhood of which is enlivened with several handsome seats; but no one is more remarkable for the excellence of its position and the singularity of its design than a lately-erected residence of Admiral Gell’s. The road continues scenic and entertaining to the small village of TRETOWER, only to be noticed for a few picturesque fragments of its castle, once the residence of Mynarch lord of Brecon. Then winding round a conical eminence, the road ascends a mighty hill called the Bwlch, which term signifies a rent in a mountain: during which ascent, a farewel view of the vale of the Usk, with a small tributary valley, and its appendant stream descending from some gloomy mountains to the north, and joining it near the castle of Tretower, is truly interesting and grand. But from these wide-ranging views, and all external scenery, the tourist becomes shut up on entering the pass of the mountains, a sterile hollow, from which he emerges on a subject of an entirely opposite and very singular description. Surrounded by dark mountains, melancholy and waste, appears an extensive lake called LANGOR’S POOL, upwards of six miles in circumference; which, as the natives assure you, is the site of a large city swallowed up by an earthquake, and is so well furnished with perch, tench, and eels, as to be one-third fish to two-thirds water.