After halting an hour we rode up a slope whose obtuser talus showed that we were reaching the far-famed platform, called Las Cañádas del Pico. The word, here meaning level ground, not, as usual, a canefield, applies especially to the narrow outer rim of the hollow plain; a bristling fortification of bluffs, pointing inwards, and often tilted to quoins 300 feet high, with an extreme of 1,000. Trachyte and basalt, with dykes like Cyclopean walls, are cut to jagged needles by the furious north-easter. Around the foot, where it is not encumbered with _débris_ like the base of an iceberg, a broad line of comminuted pumice produces vegetation like a wady-growth in Somali Land. The central bed allows no short cut across: it is a series of rubbish-heaps, parasitic cones, walls, and lumps of red-black lavas, trachytes, and phonolites reposing upon a deluge of frozen volcanic froth ejected by early eruptions. The aspect was rejoicing as the Arabian desert: I would willingly have spent six months in the purest of pure air. These flats of pumice, 'stones of emptiness,' loose incoherent matter, are the site of the first great crater. Tenerife is the type of a three-storied volcano, as Stromboli is of one and Vesuvius of two stages. The enormous diameter of this ancient feature is eight by seven miles, with a circumference of twenty-three--greater even than Hawaii--and here one feels that our earth was once a far sublimer scene. Such forms belong to the earlier volcanic world, and astronomers still suspect them in the moon. [Footnote: Las Cañádas was shown to be a volcanic crater in 1803 by Professor Cordier, the first scientific visitor in modern days (_Lettre à Devilliers fils_), and in 1810 by D. Francisco Escobar (_Estadistica_). They make the old vent ten leagues round.] The altitude is 6,900 feet, nearly double the height of Vesuvius (3,890 feet); and the lines sweep upwards towards the Pilon, where they reach 8,950 feet.