While we watched this scene a smart thunderstorm passed over, with the result that shortly afterwards the vultures spread their huge wings to dry, displaying attitudes some of which we endeavour to sketch--see also p. 9. [Illustration: "WING-DRYING"] The descent into the unseen depths beneath was rewarded, despite a terrible scramble--part of the way on a rope--by discovering a fairy grotto filled with pink, azure, and opalescent stalactites and stalagmites. The bed of the canyon, which from above had appeared to be paved with sand, now proved to consist of boulders ten feet high. After threading a devious course through these for half-a-mile we reached the mouth of the grotto. Its width would be nearly 200 feet and height about half that, the form roughly resembling the quarter of a cocoa-nut. The dome, in delicate colouring, passes description--the apex bright salmon-pink, changing, as it passed inwards, first into clear emerald, then to dark green, and finally to indigo; while the reflected sunlight filtering down between the rock-walls of the canyon caused phantasmagoric effects such as, one thought, existed only in fairyland. The cavern was backed by pillars of stalactites resembling the pipes of a mighty organ, and of so soft and feathery a texture that it was surprising, on touching them, to find hard rock. The floor also was composed of great smooth stalagmites, deep brown in colour. From outside, one saw the sky as through a narrow rift between the perpendicular walls which towered up 300 feet; and above that level there again uprose the vultures' cliffs already described. * * * * * One evening we detected afar a cavern which showed signs of being the present abode of a lammergeyer. Ere reaching it, however, a keen eye descried one of these birds in the heavens at an altitude that dwarfed the great _Gypaëtus_ to the size of a humble kestrel. Presently, after many descending sweeps, the lammergeyer entered another cavern 2000 feet higher up--in fact, close under the sky-line, among some scanty pinsápos. The hour was 4 P.M., and after a long day's scramble, the writer shied at a fresh ascent. Not so my companion, L., who set off at a run, and within an hour had reached the eyrie. It proved empty, though the leg of a freshly killed kid lay half across the nest. This was presumably the alternative site, used, this year, merely as a larder; but time did not that night admit of further search.