82.7/19 Castillo de San Marcos 1672–1821

During the first hundred years, 1565–1665, nine wooden forts were built to protect St. Augustine and the Spanish territories. But English pirates, such as Francis Drake, 1586, and John Davis, 1668, after the Spanish galleons filled with gold from the New World, made surprise attacks and sacked the city. The Spanish Queen, Mariana, ordered a stone fort to be built. The massive Castillo de San Marcos was built (1672-1695) with high, thick stone walls, and numerous canon. It was an impregnable and permanent defense at the ocean inlet to the bay of San Agustín.

Castillo de San Marcos

Not only were the walls very thick, up to 12 feet, and high, 28 feet, with a moat below, but the walls were made from coquina stone which is soft and tough, but not brittle, so it did not shatter under cannon fire.

The entrance is across a drawbridge over a moat

But the real strength of the Castillo was its 77 cannons that could fire shells more than a mile to keep ships from coming in close.

Numerous long range cannons
were the real deterrent to attacks from warships

For other targets, the mortars provided a deadly curtain of fire. The mortar pictured below used 15" shells and has a range of 1.2 miles. Several kinds of shells were used: solid iron, explosive with a rudimentary shaped charge, antipersonnel shrapnel, and incendiary.

The mortar was capable of dropping explosive shells
behind enemy siege walls

The British kept attacking from the Carolinas, but were never able to breach the Castillo, although St. Augustine was burned and rebuilt several times. In 1702, during The Queen Anne’s War, the English from Charles Town (Charleston) laid siege on the fort with 500 soldiers and Indians and several warships. They were held off by 200 Spanish soldiers, while the fort was refuge for 1,300 civilians. The siege lasted fifty days until a Spanish fleet came from Cuba and drove off the English.


The city of St. Augustine was 256 years old as the United States formally took possession of the province of East Florida. On July 10, 1821, the Spanish flag was lowered from atop the Castillo de San Marcos and replaced by the Stars and Stripes to the accompaniment of canon salutes.

Castillo de San Marcos is a National Monument
administered by the National Park Service

On weekends volunteers from local residents fire several rounds of salutes with flintlock muskets and as a finale fire a field cannon.

After each volley, the row behind steps forward to fire,
while the first row reloads

All the noise and fire and smoke is very dramatic

The fort flies the Spanish flag of the 1600s.