The fortress of San Juan de Ulua, now a prison, and which is reached by a short sail through the shark-infested harbour, is an interesting structure and has seen many vicissitudes. Used as a fort for several centuries by the Spaniards, it has successively been occupied by the French, Americans, and again by the French and their allies in the war of the intervention. The buildings in Vera Cruz are nearly all low, one-storied structures of adobe, and the walls are tinted in red, yellow, blue and green, thus furnishing to the eye a pleasing variety and, with the bay, reminding one of Cadiz in old Spain. There is an attractive plaza and an imposing avenue of the cocoanut palm. Vera Cruz is the gateway to the capital and many millions of imports and exports pass through here each year, as much as at all the other ports of Mexico combined, leaving out Progresso, on the Yucatan coast, through which the henequen traffic is carried. Tampico is the second Gulf port in importance and on the completion of a direct route to the capital will be a close rival to Vera Cruz. Coatzacoalcos is the Gulf port of the Tehuantepec railway and will become an important port. The Pacific coast affords better natural harbours. Acapulco is one of the finest natural land-locked harbours in the world. Though now of secondary importance because of the absence of railroad connections, at one time this picturesque harbour sheltered the old Spanish galleons engaged in the East India trade. Their freight was unloaded there and transported overland on the backs of burros and mules to Vera Cruz and re-shipped to Spain. Manzanillo is an important seaport on that coast and will soon be connected by rail with the capital, when its importance will be greatly increased. Other important ports on that coast are Mazatlan, Guayamas, San Blas and Salina Cruz, the Pacific port of the Tehuantepec route, where the great harbour is nearly completed.