"Well, Dias, we have found the place where the treasure is hidden, but I don't think that we are much nearer. Certainly we have not strength sufficient to clear away those fallen stones, and probably the cave is blocked by a wall several feet thick. We should want tools and blasting-powder to get through it. No doubt it is a natural cave, and it seems to me probable that they altered the course of the stream above, so that it should fall directly over the entrance. I think before we talk further about it we will go up there and take a look at it. If we find that the course has been changed that will settle the matter."
It took them an hour to climb the hill and make their way down to the gorge through which the river ran. They examined it carefully.
"It must always have come along here," Dias said. "There is no other possible channel; but there are marks of tools on the rocks on each side of the fall, and the water goes over so regularly that I think the rock must have been cut away at the bottom."
"It certainly looks like it, Dias. The rocks widen out too, so that however strong the rush of water may be it will always go over in a regular sheet. Let us follow it along a little way."
Fifty yards farther on, the gorge widened out suddenly, and they paused with an exclamation of astonishment. Before them was a wide valley, filled to the spot where they were standing with a placid sheet of water four or five hundred yards wide, and extending to another gorge fully a mile away. Bertie was the first to find his voice.
"Here's a go! Who would have thought of finding a lake up in the hills here?"
"I did not know there was one," Dias said. "I have never heard of it. But that is not strange, for no one who came up the valley would dream that there was anything beyond that fall."
Harry had sat down and thought for some minutes, looking over the lake without speaking.
"I am afraid, Dias," he said at last, "that your tradition was a true one after all, and that the gold lay in the bed of a stream in the valley we now see filled up."
"But it must always have been a lake, señor," Dias said after thinking for a minute, "and could not have been shallower, for there is no other escape than the waterfall; and however heavy the rains it could not have risen higher, except a few feet, as one can see by the face of the rock."