Less than a league from the city to the west, is the porphyritic rock of _Chapoltepec_,[4] which rises one hundred and sixty feet above the plain. On its summit is a palace or castle built by the Viceroy Galvez, but never finished. Towards the city it bears the appearance of a fortress, and the work is so constructed as to withstand a siege. The founder, no doubt, had it in view in its construction, as the resort of the Viceroy in case of insurrection among the people, of which there had been several instances. The view of the city and plain of Mexico from this spot, is remarkably beautiful. Baron Humboldt, whose enthusiasm sometimes led him to extravagance, thus eloquently describes it:[5] "Nothing can be more rich and varied than the picture which the valley presents, when, on a fine summer's morning, the heaven being cloudless and of that deep blue which is peculiar to the dry and rarified air of high mountains, we ascend one of the towers of the Cathedral of Mexico, or the hill of _Chapoltepec_. A beautiful vegetation surrounds this hill. The ancient trunks of cypress, of more than fifteen or sixteen metres[6] in circumference, divested of foliage, rise above those of the schinus, which, in figure, resemble the weeping willows of the east. In the depth of this solitude, from the top of the porphyritic rock of _Chapoltepec_, the eye overlooks a vast plain with well cultivated fields, which extend even to the foot of the colossal mountains, covered with perpetual ice. The city seems washed by the waters of the lake of _Tescuco_, whose basin, surrounded by villages and hamlets, reminds one of the most beautiful lakes of the mountains of Switzerland. Long avenues of elms and poplars lead on all sides to the capital. Two aqueducts, constructed upon lofty arches, cross the plain, and present an aspect both agreeable and interesting. To the north is seen the magnificent convent of Our Lady of _Guadalupe_, with the mountains of _Tepexacac_ behind it, among ravines which furnish shelter to dates and tufted yuccas. To the south, the whole country between _San Angel_, _Tacubaya_, and _San Agustin de las Cuevas_, appears an immense garden of oranges, peaches, apples, cherries, and other European fruit trees. The beautiful cultivation is contrasted with the savage aspect of the bald mountains which enclose the valley, and among which are distinguished the famous volcanoes of _Puebla_, the _Popocatepetl_, and _Iztaccihuatl_. The first forms an enormous cone, whose crater, constantly inflamed, throwing out smoke and ashes, opens in the midst of eternal snows." [Footnote 4: _Chapoltepec_ signifies the mountain of grasshoppers; from _Chapolin_, a grasshopper, and _tepetl_, mountain.] [Footnote 5: Vol. 2, Book 3, c. 8.] [Footnote 6: About fifty English feet.]