For two or three miles round the mountain raised by this eruption, all is barren, and covered with ashes; this ground, as well as the mountain itself, will in time certainly be as fertile as many other mountains in its neighbourhood, that have been likewise formed by explosion. If the dates of these explosions could be ascertained, it would be very curious, and mark the progress of time with respect to the return of vegetation, as the mountains raised by them are in different states; those which I imagine to be the most modern are covered with ashes only; others of an older date, with small plants and herbs; and the most ancient, with the largest timber-trees I ever saw: but I believe the latter are so very ancient, as to be far out of the reach of history. At the foot of the mountain, raised by the eruption of the year 1669, there is a hole, through which, by means of a rope, we descended into several subterraneous caverns, branching out and extending much farther and deeper than we chose to venture; the cold there being excessive, and a violent wind frequently extinguishing some of our torches. These caverns undoubtedly contained the lava that issued forth, and extended, as I said before, quite to Catania. There are many of these subterraneous cavities known, on other parts of Etna; such as that called by the peasants La Baracca Vecchia, another La Spelonca della Palomba (from the wild pigeons building their nests therein), and the cavern Thalia, mentioned by Boccaccio. Some of them are made use of as magazines for snow; the whole island of Sicily and Malta being supplied with this essential article (in a hot climate) from Mount Etna. Many more would be found, I dare say, if searched for, particularly near and under the craters from whence great lavas have issued, as the immense quantities of such matter we see above ground, must necessarily suppose very great hollows underneath.