All these waters flow down, on the south, from the main Caucasian range; on the west, from the Andian offshoot; and on the east, from that of the Kaitach; which two latter running, the one north-easterly and the other north-westerly until they meet, form the two sides of a triangle of mountains having for its base the high Caucasus. The apex is just below Himri, and consists of the escaped cliffs of two summits called the Touss-Tau and the Sala-Tau; while through a gorge between them is precipitated the whole volume of the united branches of the Koissu. Himri, accordingly, together with the neighboring fortified aoul of Akhulgo, is one of the keys of this triangular region of well-watered highlands, which is inhabited by a considerable number of warlike tribes known collectively as the Lesghians, and which, with the territory of Daghestan on the east, and that of Tchetchenia on the north, is the principal theatre of the great military achievements of Schamyl. The aoul of Himri is placed like an eagle's nest high on a rock projecting from the mountain side. From the beautiful vale through which winds the Koissu, a narrow path cut out of the rock is carried zig-zag up a height of two or three hundred feet, and is exposed to be swept by stones let loose from above of any enemy that might be daring enough to attack this strong-hold. A triple wall supported by high towers adds the defences of art to those of nature; while above, the place is sheltered by the overhanging brow of the mountain. Standing on one of these towers the native looks down upon the narrow but fertile valley, divided in twain by the fast-flowing river. Several of the surrounding mountains are laid out in terraced gardens; while some are partially covered with oaks and plane-trees; and others again are entirely bare, having instead of the drapery of foliage only the tints of gold or purple which the rising and the setting sun sheds over the ruggedness of the limestone and the porphyry. Near at hand are seen one or two heights which are clad with perpetual snows; while westward, far away beyond the lower highlands, the view is terminated by the white form of Mt. Kasbek.