Near this fall is Porthogo Cavern, through which the river Vendre runs. The water was too high to admit our entrance; our conductor, however, informed us he had penetrated about half a mile, but found the river wind so many ways, he judged it safer to return, lest he should share the fate of a poor man, who lost himself in this cavern for the space of three days. On our return a very intelligent gentleman, staying in the neighbourhood, strenuously recommended us to descend a steep mountain, on our left, to survey a curious quadrangular strata of marble in the rock below. With some difficulty we effected our purpose, having waded twice through the river. This strata in Welsh is called _bwr maen_, which signifies a stone bow: it is situated close to the river Dynnas, which, forcing its way through some broken fragments of the rock, forms a cascade a little above. The price offered for this grey marble, in London, is fifteen shillings a foot square. About five miles from Vechan, is the seat of Mrs. Holbrow, on the right. We were prevented visiting the waterfalls of Melincourt and Aperdulas, the river, owing to the late floods, being too deep to ford. Our route still continued through the valley we had so much admired the evening before. As we drew near NEATH, the tower of Knole Castle had a pleasing effect from a distance: it was built by Sir Herbert Mackworth, and is at present in the possession of H. I. Grant, Esq. The windows from the banqueting-room command a circle of many miles in diameter, composed of Neath valley and river, with the smoky town of Neath—the Mumbles’ Point—Swansea, and the Channel. The artificial cascade is well contrived; but, after the foaming torrents of Scotenogam and Culhepste, appears very tame.