The boundaries of Media are given somewhat differently by different writers, and no doubt they actually varied at different periods; but the variations were not great, and the natural limits, on three sides at any rate, may be laid down with tolerable precision. Towards the north the boundary was at first the mountain chain closing in on that side the Urumiyeh basin, after which it seems to have been held that the true limit was the Araxes, to its entrance on the low country, and then the mountain chain west and south of the Caspian. Westward, the line of demarcation may be best regarded as, towards the south, running along the centre of the Zagros region; and, above this, as formed by that continuation of the Zagros chain which separates the Urumiyeh from the Van basin. Eastward, the boundary was marked by the spur from the Elburz, across which lay the pass known as the Pylse Caspise, and below this by the great salt desert, whose western limit is nearly in the same longitude. Towards the south there was no marked line or natural boundary; and it is difficult to say with any exactness how much of the great plateau belonged to Media and how much to Persia. Having regard, however, to the situation of Hamadan, which, as the capital, should have been tolerably central, and to the general account which historians and geographers give of the size of Media, we may place the southern limit with much probability about the line of the thirty-second parallel, which is nearly the present boundary between Irak and Fars. The shape of Media has been called a square; but it is rather a long parallelogram, whose two principal sides face respectively the north-east and the south-west, while the ends or shorter sides front to the south-east and to the northwest. Its length in its greater direction is about 600 miles, and its width about 250 miles. It must thus contain nearly 150,000 square miles, an area considerably larger than that of Assyria and Chaldaea put together, and quite sufficient to constitute a state of the first class, even according to the ideas of modern Europe. It is nearly one-fifth more than the area of the British Islands, and half as much again as that of Prussia, or of peninsular Italy. It equals three fourths of France, or three fifths of Germany. It has, moreover, the great advantage of compactness, forming a single solid mass, with no straggling or outlying portions; and it is strongly defended on almost every side by natural barriers offering great difficulties to an invader.