From the broad reach just below Bazias the whole horizon to the south and east appears to be a solid wall of rocky heights, and is without a break visible to the eye. For about twenty miles the river winds gently across a pleasant valley, divides around a large island, and then sweeps straight down towards the huge barrier, which extends to the right and left as far as the eye can see. As we paddled along in the quiet current past the Servian town of Gradistje, and came nearer and nearer to the mass of rugged peaks which cut sharply against the sky, we grew more and more impatient to discover the course of the river through the chain, and unconsciously increased the rapidity and the force of our stroke until we sped along as if paddling a race. Suddenly, as we were passing the end of the large island, the landscape opened to the eastward like the shifting scenes on a stage, and the river, sweeping past a high isolated rock in mid-stream, was seen to plunge with accelerated speed directly into a narrow cleft between immense limestone cliffs, and to disappear in the depths of the gorge. Guarding the entrance to this defile, the ruin of the Castle of Golubáç, on the Servian shore, piles its towers high on a spur which juts out boldly over the river, and shades a pleasant little green meadow by the water-side. The foundations of the castle are said to be Roman, and there is a tradition that Helen, the Empress of Greece, was imprisoned here; but the ruins now visible are those of the fortress built by Maria Térésa in the middle of last century. Along the Hungarian bank the famous highway of Count Széchényi, leading from the town of Moldova just above to Orsova, at the Roumanian frontier, shows the straight line of its cuttings and embankments but a few feet above the water. The smooth, perpendicular cliffs are perforated by numerous caverns, one of which tradition has marked as the place whence issue the swarms of vicious flies which persecute the cattle in the summer-time. A local legend attributes the origin of these flies to the body of the dragon killed by St. George.