On the peninsula formed by the junction of the Isla with the Tay are the remains of a strong and massive vallum, called Cleaven Dyke, extending from the one river to the other, with a small Roman fort at one end, and enclosing a large triangular space capable of containing Agricola’s whole troops, guarded by the rampart in front and by a river on each side. Before the rampart a plain of some size extends to the foot of the Blair Hill, or the mount of battle, the lowest of a succession of elevations which rise from the plain till they attain the full height of the great mountain range of the so-called Grampians; and on the heights above the plain are the remains of a large native encampment, called Buzzard Dykes, capable of containing upwards of 30,000 men. Certainly no position in Scotland presents features which correspond so remarkably with Tacitus’s description as this, and we may suppose the Roman army to have occupied the peninsula protected by the rampart of the Cleaven Dyke in front, and Calgacus’s native forces to have encamped at Buzzard Dykes. These two great armies would thus remain opposed to each other at the distance of about three miles, the one containing the whole strength of the native tribes still unsubdued, collected from every quarter, and amounting to upwards of 30,000 men in arms, while the youth of the country, and even men in years, were still pouring in, and resolved to stake the fortunes of their wild and barren country upon the issue of one great battle; the other, the Roman army of veteran troops, flushed with past conquests, and confident in the well-proved military talent of their general;—the one on the verge of their mountain country, and defending its recesses, as it were, their last refuge; the other at the termination of the extensive regions they had already won from the Britons, and burning with desire to penetrate still farther, even to the end of the island. Between them lay the Muir of Blair, extending from the rampart at Meikleour to the Hill of Blair. On the east both armies were prevented from extending in that direction, or from outflanking each other, by the river Isla. On the west a succession of morasses, moors, and small lochs extends towards the hills, and in this direction the battle eventually carried itself.[53]