They chose, therefore, upon the map the valley of that torrent called the Aston, and before it was evening, but at an hour when the light of the sun was already very ripe and low, they stood under a great rock called Guie, which was all of bare limestone with façades as bare as the Yosemite, and almost as clean. They looked up at this great rock of Guie and made it the terminal of their attempt. I was one and my companion was the other: these were the Two Men who started out before a sunset in August to conquer the high Pyrenees. Before me was a very deep valley full of woods, and reaching higher and higher perpetually so that it reminded me of Hyperion, but as for my companion, it reminded him of nothing, for he said loudly that he had never seen any such things before and had never believed that summits of so astonishing a height were to be found on earth. Not even at night had he imagined such appalling upward and upward into the sky, and this he said though he had seen the Alps, of which it is true that when you are close to them they are very middling affairs; but not so the Pyrenees, which are not only great but also terrible, for they are haunted, as you shall hear. But before I begin to write of the spirits that inhabit the deserts of the Aston, I must first explain, for the sake of those who have not seen them, how the awful valleys of the Pyrenees are made. All the high valleys of mountains go in steps, but those of the Pyrenees in a manner more regular even than those of the Sierra Nevada out in California, which the Pyrenees so greatly resemble. For the steps here are nearly always three in number between the plain and the main chain, and each is entered by a regular gate of rock. So it is in the valley of the Ariege, and so it is in that of the Aston, and so it is in every other valley until you get to the far end where live the cleanly but incomprehensible Basques. Each of these steps is perfectly level, somewhat oval in shape, a mile or two or sometimes five miles long, but not often a mile broad. Through each will run the river of the valley, and upon either side of it there will be rich pastures, and a high plain of this sort is called a _jasse_, the same as in California is called a "flat": as "Dutch Flat," "Poverty Flat," and other famous flats.