Before Hugh, as he spoke, loomed the White Castle, the immense fortification which linked the land walls of Constantinople with the sea walls fronting the Bosphorus. Above the frowning barriers, crowded with people, showed a mass of towers and pinnacles, stretching away as far as the eye could see. In this end of the city were the poorer quarters, the slums and the haunts of the lowly. Their houses were jammed close together, and off the main thoroughfares the streets were narrow and dark. Yet there were frequent open spaces. Here a church, there a monastery, beyond a nunnery or a tree-bordered cistern fed by aqueducts which were laid under-ground from the distant hills of Thrace. Beyond all these again showed the eastern quarters of the city, perched on their six hills and the valleys between. The seventh hill--for like Imperial Rome, Imperial Constantinople boasted her seven hills--was in the southwestern quarter. It was impossible for the eye to take in everything, but Hugh saw all that he could. What caught his attention first was the walls, ponderous, girt with hundreds of towers. To the landward they rose tier above tier, three lines of impenetrable bulwarks, fronted by a moat as broad and deep as a river. On the seaward face they were built at the water's edge with ledges of boulders to guard their foundations from the dash of the waves. At intervals, too, the serried array of the seaward towers was broken by the gap of a harbour, protected by a jetty and guarded by fortifications constructed in the sea with the same careful weight as those which owned a firm bed on land. Hugh had never seen such walls. In France, England and Italy he had seen castles built in the new fashion of splendour combined with strength which men had brought home with them from the Holy Land after contact with the master-masons of the Saracens. But neither in Western Europe nor in Paynimry were there walls like those which encircled Constantinople. They were the outstanding achievement of engineering in mediæval times. For fourteen miles they marched, from forty to more than one hundred feet high, and on the land side presenting a series of defences two hundred feet wide. They were like cliffs, giving an effect of permanence and endurance, monuments of the skill and pertinacity of man. When Hugh saw them they had lasted for nine hundred years, and although he did not know it, they were to last seven hundred years longer. His wonderment showed in his face. "By St. James!" he said reverently. "They were men who built thus! How can our puny numbers avail against such barriers?" "I know not, Hugh," returned Matteo. "An God wills us victory, it may be! But I have seen the walls of Antioch, and I tell you that though men say they could not be built again in our day, they are as nothing to what you see. Constantinople is a virgin city. No enemy hath ever forced her." "What is that yon?"