Castillo de San Marcos National Monument

St. Augustine, Florida: Standing guard over St. Augustine for over 300 years, Castillo de San Marcos is the oldest fort in the United States. The fort has been home to four separate military occupations and now spends its days as a national monument.

When the Spaniards founded the city of St. Augustine in 1565, it quickly went to work building a series of wooden forts to protect the city. However, several pirate attacks demonstrated a weakness in the wooden forts and the Spanish Crown ordered the construction of a masonry fort.

Construction of the fort began in 1672 and lasted until 1695. It was constructed with a mixture of small shells and sand called coquina which was mined from nearby King’s Quarry located at present day Anastasia State Park. The coquina was strong enough to build a long-lasting fort while having enough absorption to allow cannon balls to stick in the wall rather then going straight through.

The fort saw its first battle in 1702 at the hands of English forces. They laid siege on the fort and the city only to have they efforts unsuccessful thanks in part to the strength of the coquina walls of the fort. For nearly two months, the English ships bombarded the fort with cannon fire but it had no effect. The English realized that they would not be able to penetrate the fort and later retreated to nearby Fort Caroline.

It would be nearly forty years before another attempt to take the fort. This time the British Navy entered into Matanzas Bay with a fleet of ships. Like the previous attempt, the cannons had no effect on the fort. But rather then retreat, the ships set up a blockade on the bay, preventing food and supplies from reaching the 1,600 Spaniards in refuge behind the walls of the fort. The tactic was successful; however the British fleet was low on their supplies so they retreated before taking over the fort or city.

Great Britain finally took possession of Castillo de San Marcos in 1763 following the Treaty of Paris. They renamed it Fort St. Mark. It was later used to house prisoners of war during the American Revolutionary War.

The fort later returned back to Spain following the Revolutionary War and Spanish troops returned to the fort. The fort remained in Spanish control until 1819 when Spanish Florida was turned of to the United States with the Adams-Onis Treaty.

The Americans took over the fort in 1819 and renamed it Fort Marion. It was further enhanced to become part of the American coastal defense system. The fort saw action during the Second Seminole War in 1837, mainly as a prison.

The fort changed hands once again in 1861 as Florida seceded from the Union. Confederate troops peacefully overtook the fort and used it to house the St. Augustine militia.

Union forces regained possession of the fort in 1862. Navy fleet entered the harbor to find that confederate forces had already retreated from the town. They were able to retake the fort without firing a shot.

The United States turned the fort back into a prison for Native Americans. It functioned in this capacity until 1900 when it was removed from active duty.

In 1924, it was declared a National Monument and was later turned over to the National Park Service. The fort reverted back to its original Spanish name Castillo de San Marcos and would later be added to the National Register of Historic Places in 1966.

Today the 2 ½ acre park plays hosts to thousands of visitor’s each day. You can tour the fort on a self-guided tour or follow on of the many ranger guided tours. On select days, they demonstrate how the cannons were fired or witness a reenactment from certain eras of the forts history.

The park is currently operated by the National Park Service. Admission to the fort is $6 for adults and children 15 or under are free. NPS passes are accepted for admission to the fort. Limited parking is available on-site for $1.50 per hour or at the nearby city parking garage for $10 a day.

Click on the photo above for photos from Castillo de San Marcos National Monument.