The castle at Acapulco, an extremely important point on the southern or Pacific coast, is greatly impaired, and will require at least a hundred thousand dollars to adapt it for defence. The fortress of Perote was designed originally by the Spanish government as a depot for the treasure intended for shipment from Vera Cruz, in which the gold and silver would be safer than at an exposed sea port during that dangerous period of Castilian history, when all the nations of Europe were anxious to plunder her colonies. Situated far in the interior of the country and in the midst of a wide plain, it does not absolutely command any of the approaches either from the coast to the inner states, or to the coast from the capital. It is, however, well placed as a military arsenal, and demands an expenditure of about thirty thousand dollars to render it useful to the nation. The Castle of San Juan de Ulua, built on a reef opposite the town of Vera Cruz, is in so ruinous a state that scarcely a million and a half of dollars will suffice to restore it to its ancient splendor and power. The one hundred and twenty-four guns now within its walls are all more or less injured or dismounted. "To garrison this Castle properly," said General Arista in his report as Minister of War in 1849, "two thousand men will be required at a yearly cost of four hundred thousand dollars. If this immense treasure is squandered on the Castle, it will surely be wasted alone to preserve a vain luxury; for, as Mexico has no hope of becoming a maritime power, San Juan de Ulua must always fall into the possession of such a naval nation whenever it makes war upon us. Experienced Spanish officers have recommended the dismantling of San Juan, and they now urge it more strongly than ever, as there is far greater reason to believe that it neither defends the nation nor even the city of Vera Cruz. The French, and recently the Americans, have convinced us of this fact; the first possessed themselves early of the Castle, and the latter took the town without hindrance from the Castle." Such is the opinion of one of the most experienced Mexican generals in regard to a fortress which has hitherto been deemed impregnable, and, although we do not agree with him in regard to its entire worthlessness in the hands of abler engineers, we doubt whether its use is not greater in checking the city of Vera Cruz itself, than in commanding the approaches to it from the sea. It must be remembered that the lee of this very Castle is the only comparatively safe harbor on the gulf at present, and that until a _mole_ or breakwater shall be erected elsewhere, it is only in certain seasons and under favorable circumstances that large bodies of troops may be prudently disembarked on the adjacent shores. The landing of General Scott, in 1847, was singularly fortunate in time and circumstances, for, soon after, a furious norther arose and prevented all communication between the land and the squadron.