Servia, within its actual limits, includes only a small portion of the northern slope of the mountains rising in the centre of the Balkan peninsula. It is separated from Austro-Hungary by the Save and the Danube, but no natural boundary divides it from Turkey; and the valleys of the Morava, the Drina, and the Timok, the former in the centre, the others on the eastern and western frontiers of the country, afford easy access to a foreign invader. The difficulties to be surmounted by the latter would begin only after he had entered the vast forests, the narrow valleys, and unfathomable _klisuras_ amongst the mountains. The only plains of any extent are on the banks of the Save. Everywhere else the country is hilly, rocky, or mountainous. The most prominent mountain range is that which extends from the “Iron Gate” and the defile of Kasan, on the Danube, through Eastern Servia, and forms a marked continuation of the Transylvanian Alps, with which it agrees in geological structure. In the northern portion of these Servian Carpathians, in the angle formed by the confluence of the Danube and Morava, where masses of porphyry have burst through limestones and schists, we find ourselves in the great mineral region of Servia. Copper, {173} iron, and lead ores are being worked here, especially at Maidanpek and Kuchaina, but the old zinc and silver mines have been abandoned. The valley of the Timok, in the southern portion of this mountain range, is likewise rich in minerals, and gold dust is collected from the sand of the river. There are few valleys which can rival that of the Timok in beauty and fertility, and the basin of Knyashevatz, where the head-streams of the river unite, is more especially distinguished by its rural beauty, sparkling rivulets flowing through the meadows, vines covering the hills, and forests the surrounding mountains. A narrow defile immediately below this basin leads into the valley of Zaichar, near which, at Gamzigrad, there still exist ruins of a Roman fortress, its walls and towers of porphyry in a capital state of preservation. Looking northward from this position we perceive the Stol (3,638 feet), whilst in the south-west there rises a huge pyramid of chalk, which might almost be mistaken for the work of human hands. This is the Rtan (4,943 feet), at whose foot burst forth the hot springs of Banya, the most frequented and efficacious of all Servia.