"I want you to notice," he observed, "that this stone was _cemented_, and this little stream of water that has accidentally found its way round here, has, in the course of time, loosened the cement; else I could not have pushed the stone away. We should have had to blast it." "Yes," said Jack; "and it also shows that it was closed _from the inside_. Whoever last closed it never went out again--at least not by this entrance. Where then did they go to?" "That's what we have to see about," returned Monella. "Now, follow me, and I will show you something that will surprise you." CHAPTER VII. THE CANYON WITHIN THE MOUNTAIN. Monella, with the lantern in his hand, led his two companions through an arched opening into a second cavern which seemed to be larger and loftier than the first; and this, in turn, opened into a third, at one end of which they could see that daylight entered. Monella stopped here and, lifting the light high in one hand, pointed with the other to side-openings in the rock. "They are side-galleries, so to speak," he said, "but do not appear to be of any great extent. I have been to the end of two or three. They all seem to be perfectly empty too; not so much as a trace of anything did I see, save loose pieces of stone here and there, that had, no doubt, fallen from the roof. Now we will go to the entrance on this side." And he turned and walked on towards the place where they could see the glimmering of daylight. Quite suddenly they turned a corner and saw before them a high archway, leading out into the open air; and, before the two young men had had time to express surprise, they had stepped out of the gloomy cavern into a valley, where they stood and stared in helpless astonishment upon a scene that was as lovely and enchanting as it was utterly unexpected. They saw before them the bottom of a valley, or canyon, of about half a mile in length, and nearly a quarter of a mile in width; its floor, if one may use the expression, consisted chiefly of fine sand of a warm tawny hue; its sides, of rocks of white or pinkish white fine-grained sandstone, with here and there veins, two or three feet wide, of some metallic-looking material that glistened in the sunlight like masses of gold and silver. In other places were veins of jasper, porphyry, or some analogous rock, that sparkled and flashed as though embedded with diamonds; other parts again were dark-coloured, like black marble, throwing up in strong relief the ferns and flowers that grew in front of them.