A few rods to the north of the town stands the castle of San Carlos--a square fort, with a moat and glacis. It is built in the best style of fortifications of the last century, having been designed as a depository for silver, when, in consequence of the wars of Spain with maritime nations, it was not deemed prudent to send it forward to the coast: it was much used for this purpose when the road below was blocked up, in the times of the insurrection, that began in the year 1810. At one time the accumulation here was so great that it is said to have amounted to 40,000,000 of silver dollars; weighing about 1300 tons, or a little short of the whole silver export of two years. This castle is now in a fine state of repair. It has a large garrison of lancers, and at the time of my visit was daily in expectation of the arrival of Santa Anna. From this castle Santa Anna, in 1828, issued his _pronunciamiento_ against Pedraza. In this castle he was imprisoned by Rincon, in 1845, after his capture at Xico. From this castle he was banished by decree of the Mexican Congress; and to it he was now returning to hold the supreme power in the State.
At two o'clock in the morning we were aroused from our comfortable beds to take our places in the stage; and soon we were again upon the road. There is something exceedingly attractive in the appearance of the skies upon this elevated table-land, 7692 feet above the ocean. The morning star-light is very beautiful. It is so much clearer, and the stars are therefore so much brighter here than in the dense atmosphere where we inhabit, that the traveler, half chilled and sleeping, rouses himself to contemplate the brilliant sights above him. The brightest stars that he has watched from childhood up, are brighter now than ever. New stars have filled the voids in his celestial chart, and satellites are dancing round well-known planets. The North Star is still visible, now 19° above the horizon. The Dipper has dipped far down to the northward. The Southern Cross--that mysterious combination of five stars, that emblem of the faith of Southern America, which only reaches full meridian at midnight prayers--is here 25° above the horizon, shining brilliantly. And then there are so many unknown southern stars, and so many unfamiliar constellations, that the short hours of night are well spent upon the driver's box.