Those who may distrust the accounts of Peruvian industry will find their doubts removed on a visit to the country. The traveler still meets, especially in the central regions of the tableland, with memorials of the past, remains of temples, palaces, fortresses, terraced mountains, great military roads, aqueducts, and other public works, which, whatever degree of science they may display in their execution, astonish him by their number, the massive character of the materials, and the grandeur of the design. Among them, perhaps the most remarkable are the great roads, the broken remains of which are still in sufficient preservation to attest their former magnificence. There were many of these roads, traversing different parts of the kingdom: but the most considerable were the two which extended from Quito to Cuzco, and, again diverging from the capital, continued in a southerly direction toward Chili. One of these roads passed over the great plateau, and the other along the lowlands on the borders of the ocean. The former was much the more difficult achievement, from the character of the country. It was conducted over pathless sierras buried in snow; galleries were cut for leagues through the living rock; rivers were crossed by means of bridges that swung suspended in the air; precipices were scaled by stairways hewn out of the native bed; ravines of hideous depths were filled up with solid masonry; in short, all the difficulties that beset a wild and mountainous region, and which might appall the most courageous engineer of modern times, were encountered and successfully overcome. The length of the road, of which scattered fragments only remain, is variously estimated at from fifteen hundred to two thousand miles; and stone pillars, in the manner of European milestones, were erected at stated intervals of somewhat more than a league, all along the route. Its breadth scarcely exceeded twenty feet. It was built of heavy flags of freestone, and, in some parts at least, covered with a bituminous cement, which time has made harder than the stone itself. In some places where the ravines had been filled up with masonry, the mountain torrents, wearing on it for ages, have gradually eaten away through the base, and left the superincumbent mass--such is the cohesion of the materials--still spanning the valley like an arch.