It is uncertain when the name St. Mark’s was first applied to the castle, though probably during the English occupation, 1663-1684. The fort, doubtless, acquired the name from that applied to the present north river, which was called by the Spaniards St. Mark’s River, at the mouth of which the fort is located. It is probably the oldest fortification now standing in the United States, and certainly the oldest which is yet in a good state of preservation. From the date at which the Apalachians began work, until the year in which the fortification was declared finished and the commemorative tablet erected, the period during which it was being built is one hundred and eighteen years. It has now been a century and a quarter since this magnificent old structure, representing the grandest military architecture of the middle ages, was completed, and two centuries and a half since its inception. What a strange and eventful history is connected with its stone walls, its deep ditch, its frowning battlements, its dismal dungeon, and damp casemates, in the midst of which, on the north side, is its chapel with raised altar, built into the masonry, and holy water niches in the walls of the casemates. Those who have read this history thus far will have noted the laying of its foundations by the hands of those zealous and bigoted Catholics who had exterminated a settlement of the subjects of a friendly nation, lest they should spread among the barbarous Indians heretical doctrines; the accretion of its rising walls under the hands of the unfortunate Indians, who had been loath to accept the Christian teachers and doctrine that had been forced upon them by these expungers of heresy, until, with the aid of convicts and king’s workmen, the work was completed, to stand the defense of the Spanish possessions in Florida, the protection of fugitive slaves, depredating Indians, Spanish pensioners and adventurers, and the prison of many wretched Indians and whites who had fallen under the displeasure of a Spanish autocrat. For almost two hundred years the Spanish ensign had been uninterruptedly displayed from the site of this fort, when, by the treaty of 1762, it was yielded to the British, and the cross of St. George displayed from its battlements. The year after his arrival in Florida, Governor Hereda sculptured, in alto-relievo, the Spanish coat of arms over the entrance of the fort. The tablet upon which the design is impressed is made of cement, and let into the walls of the fort. The inscription on the tablet beneath the coat of arms is as follows: “REYNANDO EN ESPANA EL SEN^{N} DON FERNANDO SEXTO Y SIENDO GOV^{R} Y CAP^{N} DE ES^{A} C^{D} SA^{N} AUG^{N} DE LA FLORIDA Y SUS PROV^{A} EL MARISCAL DE CAMPO D^{N} ALONZO FERN^{DO} HERADA ASI CONCLUIO ESTE CASTILLO EL AN OD 1756 DRI^{G}ENDO LAS OBRAS EL CAP. INGN^{RO} DN PEDRO DE BROZAS Y GARAY.” TRANSLATION: