Castillo de San Marcos

The city of St. Augustine, founded in 1565, was protected by nine wooden forts during its first hundred years. After an attack in 1668, the Spanish Crown decided to erect a more permanent defensive structure. Construction of the present-day Castillo began in October 1672 and was completed over 23 years by workers from Havana. As early as 1702, the fortress withstood a two-month siege by British troops under Governor James Moore, with 1,200 residents and 300 soldiers seeking refuge inside. A Spanish fleet from Havana broke the siege, after which the British scuttled their ships and set St. Augustine ablaze. In 1738, the fort was rebuilt under the direction of engineer Pedro Ruiz de Olano, with walls reinforced and wooden ceilings replaced by stone vaults to support heavier cannons. Just one year later, in 1739, British troops under General James Oglethorpe besieged the fort again. Despite 38 days of continuous bombardment and a blockade of supply routes, the fort held, and the British retreated. In the Treaty of Paris of 1763, Florida was ceded to the British, and the fort was renamed Fort St. Mark. During the American Revolutionary War, it was declared the capital of East Florida and refurbished, but played a minor role in the war itself. In 1783, Florida reverted to Spain under the Treaty of Paris, and the fort regained its original name. After further reinforcements to secure the Spanish presence, Florida was ceded to the United States in 1821, and the fort was renamed Fort Marion. During the American Civil War, it briefly fell to the Confederates but was recaptured by the Union in 1862 and subsequently served as a prison, including for Native American leaders. From 1900, the fort no longer had a military function and was declared a National Monument in 1924; in 1942, it regained its original name, Castillo de San Marcos.

The Castillo de San Marcos is located in St. Augustine, St. John County, Florida, USA, at an elevation of approximately 8 meters above sea level.

The historic fortress can be visited by the public today and is managed as a single unit along with the Fort Matanzas National Monument.

• Fort Matanzas (fortress), approx. 21.4 km away
• Fort Caroline (fortress), approx. 57.2 km away
• Fort Frederica (fortress), approx. 147.2 km away
• Fort King George (fortress), approx. 162.8 km away