Thus advancing we at last arrive opposite to the mouth of the deep glen down which the Styx comes to join the Crathis on its western bank. Here we cross the Crathis and strike up the glen of the Styx. The scenery of the profound and narrow glen is almost oppressively grand. The mountains are immense and exceedingly massive; above they are bare and rocky; but their lower slopes are terraced so as to resemble gigantic staircases, and on the terraces are perched several very picturesque villages, the houses scattered at different levels and embowered among trees. At the upper end of the glen soars the mighty cone of Mount Chelmos. The grandeur of the scenery, which would otherwise be almost awful, is softened by the wonderful luxuriance of the vegetation in the glen. The horse-chestnut trees especially, with their enormous gnarled and knotted trunks, are a sight to see. The nightingales are said to be very common here and to sing from February to June. A long laborious ascent by a winding path brings us to the prosperous village of Solos on the eastern side of the glen. The villages on the opposite side of the glen, dispersed over the terraced slopes, form, with Solos, almost a single settlement. One of them probably occupies the site of the ancient Nonacris. LXI. THE FALL OF THE STYX.—The village of Solos stands, as we have seen, on the right bank of the Styx, near where that stream falls into the Crathis. But the source of the stream is at the head of the glen, some miles to the south, where the water tumbles or trickles, according to the season, over the smooth face of an immense perpendicular cliff, the top of which is not far below the conical summit of Mount Chelmos, a mountain nearly eight thousand feet high. The walk from Solos to the foot of the fall and back is exceedingly fatiguing, and very few travellers accomplish it; most of them are content to view the fall from a convenient distance through a telescope. For the first two miles or so the path is practicable for horses, and travellers who are resolved to make their way to the waterfall will do well to ride thus far and to have the horses waiting for them here on their return. It is also necessary to take a guide or guides. The path winds up the glen, keeping at first high on the right bank. The bed of the stream is here prettily wooded with poplars and other trees and is spanned by a bridge with a single high arch. For a considerable distance above the village the water of the Styx, as seen from above, appears to be of a clear light-blue colour, with a tinge of green. This colour, however, is only apparent, and is due to the slaty rocks, of a pale greenish-blue colour, among which the river flows. In reality the water is quite clear and colourless.