Castillo de San Marcos

Article and pictures by Tom Brennan, all rights reserved.

The Castillo de San Marcos is a stone fort built by the Spanish in 1672 to guard the harbor and town of St. Augustine, Florida - the oldest European settled town in The United States. The fort is square in plan and has four bastions, a ravelin covering the gate front, a dry ditch and a glacis with a covered way and spacious places of arms. The fort has been continuously occupied and maintained by the Spanish, British and American armies and now by the National Park Service. Thus the fort has never fallen into ruin and has not needed restoration or reconstruction.

The strategic purpose of St. Augustine was to guard the shipping route between Spain and its colonies in the New World. Because homeward bound ships sailed north along the Florida coast before turning east to Europe, the Spanish needed a presence in Florida to deter attacks on this shipping by pirates and enemies of Spain. The city was founded in 1565 by the Spanish admiral Pedro Menendez de Aviles who was sent to Florida to root out a group of Frenchmen who were attempting to establish a colony in Florida with an eye toward going into the piracy business at the expense of Spain. In short order, Menendez, a most bold and capable commander, founded St. Augustine as his base and destroyed the French.

The town was originally guarded by a series of wooden forts. Each in turn quickly grew rotten and ramshackle and was rebuilt or replaced. The failure of one of these forts to provide effective defense when the town was sacked by English pirates in 1668 prompted the Spanish government to build a proper permanent fort of stone. Money was found, an engineer named Ignazio Daza sent to design the fort and oversee the work, and in 1672 work began on the current fort. Because money and help, both skilled and unskilled, were often lacking the work went slowly and the fort was finished in 1695.

As originally built, the fort had a ditch but no glacis or covered way. The walls were about 13 feet thick at the base tapering to about 9 feet at the base of the parapet. The bastions were filled solid with earth and the curtain walls were backed by rooms which formed a courtyard, the timber roofs of these rooms forming the fort's terreplein. Because these roofs would not support cannon the cannon were placed on the bastions. The stone was covered by a layer of gleaming white plaster, remains of which can still be seen.

Of interest is the peculiar local limestone used to build the fort. It is called coquina and consists of billions of tiny sea shells cemented together by geologic pressure and their own lime. When quarried this stone is very soft and can be shaped with saws and hatchets but after a year or so of exposure to the air it hardens and is suitable for building. Being compressive, this stone when struck by cannon shot absorbed it rather than shattering, a most useful characteristic, similar to sticking your finger into a moist chocolate cake. Many visitors to the fort confuse this coquina stone with tabby - a concrete made using seashells rather than gravel as the aggregate. As well as coquina, there is also tabby to be seen around the fort, especially in the seawall, which is made of tabby poured between two coquina walls.

In 1702 during Queen Anne's War an English provincial army from the Carolina colony to the north descended upon Spanish St. Augustine. The garrison and townspeople evacuated the town and took refuge in the fort. The English occupied the town and dug trenches around the fort. The few cannon they brought were too small to harm the fort and the English gunners were in more danger than the Spanish ones. The fort was energetically defended by frequent sorties and even an expedition which drove a herd of cattle into the fort right through the English lines, the cattle then grazing in the shelter of the ditch. After almost two months a Spanish relief fleet arrived from Cuba and the English fled after burning the town and the Catholic mission of Nombre de Dios to the north of the town. Although St. Augustine dates back to 1565 its oldest buildings, other than the fort itself, date back to only the early 1700s.

Even though the English brought no mortars the Spanish defenders were very anxious about the fort's vulnerability to mortar fire and that, along with losing the town to burning, made the Spanish decide to improve the defenses of both town and fort.

The town, being at the south end of a peninsula formed by the harbor on the east and the San Sebastian River on the west, was vulnerable to land approach only from the north, so the Spanish built two earthwork lines north of the town to guard that approach. One wall, called the Cubo Line, ran from the fort to the river. (The National Park Service excavated and rebuilt the part of this line running from the fort to the present street bordering the fort.) A second line, called the hornwork, was about a half mile farther north and was a crownwork consisting of half bastions on either end and a full bastion in the middle. In addition an earthen wall was built around the town itself.

The fort was to be improved with the rooms backing the curtains rebuilt as vaulted bombproof stone casemates. These casemates were taller and deeper and capable of both resisting mortar fire and mounting cannon. The first of the fort's fronts to be rebuilt was the east one facing the harbor.

In 1740 during the War of Jenkins' Ear a British provincial army from Georgia and the Carolinas attacked St. Augustine. Though much better armed and equipped than the 1702 expedition, it faced a strong and sophisticated defensive system rather than an isolated fort and undefended town. Lacking the professional engineering and equipment needed to tackle the new works the British decided to bombard the town from Anastasia Island, the barrier island on the side of the harbor opposite the fort.

The side of the fort facing the island and harbor was the side that had been improved with the new bombproofs and more cannon - the British did little damage. After three weeks of uselessly burning powder and shot, and having suffered a small disaster when a Spanish sortie destroyed an isolated British outpost, killing about 80 Scots, the British withdrew. Thus in both 1702 and 1740 the Castillo successfully defended itself against the two assaults made upon it.

After the siege the Spanish slowly continued work on the fort, completing the bombproofs on all four walls and finally building a glacis and covered way. They also built a new larger ravelin. In 1763 all this was for naught when the British gained possession of Florida by treaty at the end of the French and Indian War (Seven Years War). During the American War of Independence the British in Florida were under considerable pressure from the Spanish in Louisiana and kept a large garrison in St. Augustine. The British renamed the castillo Fort St. Mark and improved it making the glacis higher and building traverses to prevent ricochet fire along the covered way. They also built redans on the north salient and reentrant places of arms to provide an extra layer of defense; unfortunately these traverses and redans were removed by the American army in the mid 1800s.

In 1783 the Spanish regained Florida and kept it until the Americans made Spain an "offer it couldn't refuse". The Americans bought Florida, taking possession of St. Augustine in 1821. The War Department renamed the fort, Fort Marion and found various uses for it, such as a prison for hostile western Indians : Comanches and Kiowas from the southern Great Plains and Apaches from Arizona. It seems the American army was well aware that part of its job at Fort Marion was historical preservation and in a sense, the army was acting as the National Park Service does now. When visiting the fort you'll see repairs made with red brick; those are 19th Century repairs done by the United States Army.

In 1924 the fort was declared a National Landmark and in 1933 the War Department turned it over to the National Park Service. In 1942 the NPS dropped the name Fort Marion and renamed the fort the Castillo de San Marcos and it is now called the Castillo de San Marcos National Monument.

Visiting the Castillo de San Marcos

As stated earlier, because the fort was continuously occupied and maintained since its building it never fell into ruin and thus never needed restoration or 'reconstruction'. The NPS does repairs using coquina stone and mortar of the type originally used, these repairs are easily identified because the stone is lighter in color. Currently the parapet of the covered way is being repaired.

The fort opens every day at 9AM (and is closed only on Christmas day) and if you arrive before 10AM you will easily find parking in the lot at the foot of glacis. If this lot is full there is a large city owned garage not far to the west of the fort. There is an admission fee but seniors can buy a lifetime NPS pass that gets you into all NPS parks and historic sites for no charge.

The fort is staffed by professional NPS rangers and NPS volunteers (I serve as a volunteer). Though there are no official tours, hourly talks are given and on weekends cannon are fired atop the northeast bastion. Rangers and volunteers will answer your questions, I often take people on tours of the fort, pointing out the defensive structures and talking about the history of artillery fortifications going back to the 1400s. Indeed, it's hard to shut me up. I am usually there on Tuesdays, if you're there look me up.

The fort has modern toilets and sinks, water fountains and a gift shop/bookstore. Other must see places in St. Augustine are the mission of Nombre de Dios where the Catholic Church has had a presence since 1565. The mission has a museum, an old chapel and beautiful grounds. Also worth a visit is the Alligator Farm on the south side of town, a survivor of old school Florida mom and pop tourism from the 1950s - a look at what Florida was like before Disney style attractions changed the nature of tourism. And that's history too.

Article and pictures by Tom Brennan, all rights reserved.

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