It was an ominous and an awful sight, which might well have made the bravest shrink back from those grim and crumbling walls. A large and solitary vulture sat on one of the upper keeps, and seemed to be the only watcher left in this deserted fort. He perched motionless and sharply silhouetted against the rarefied space, like an embodiment of spent disaster. Ned was the first to recover his presence of mind. Stooping down, he picked up a skull and looked at it critically. It was dry and powdery, with the combined effects of sun-bleaching and time. Holding it up in his hands, he said-- "The fellow who owned this, once upon a time, has forgotten his pains and troubles for many years--perhaps centuries. He must have been a big fellow when he carried it, with a solid brain-pan, although it has now grown thin and brittle as the finest porcelain." "A big fight has taken place here," remarked Cocoeni, holding out the rusty head of a broken spear which he had picked up, and looking at its shape curiously. The splintered shaft was like tinder, and crumbled between his finger and thumb like powder; the design of the iron was ancient and strange. "That vulture appears to be the only resident at present inside the fort," said Fred. "Suppose we have a shot at him, and try the effect, eh?" "No," replied Ned. "Keep your ammunition for worthier foes; we may need all our cartridges by-and-by. Meantime let us try to achieve what these fellows have evidently failed to do--get over the walls as quietly as possible, and discover what is behind. Keep your weapons ready for instant use, and your eyes and ears open, boys. Now, forward, in your best scaling order." They ran swiftly through the crunching bones, and up the steep sides of the cliffs. A rugged kind of hewn stairway led them up to a massive square-shaped portal, which was gateless and more than half demolished. The huge stones of the posts were bulging out, and the top bending over. As they dashed inside, the vulture rose with a hoarse scream and sailed lazily away. Inside they discovered a large courtyard, heaped with fallen masonry. Great blocks of ten and twenty feet long lay in every direction, with gaps in the walls above them, from which they had been dislodged. "By George, but they built for time here, when they were at it!" cried Clarence, looking round him with admiration. "Yes," replied Ned. "The builders of this place knew something about the pyramids." It was all of the massive, square, and Egyptian style of architecture: walls with heavy abutments at the bases; oblong narrow slits for windows and embrasures; wide spaces which had originally been covered with paintings, now only showing in undecipherable patches; massive upright slabs for pillars, with enormous flat lintels.