Ft. Matanzas National Monument on the Matanzas river

Fort Matanzas National Monument in Florida played a major part in the protection of St. Augustine. It is named both for a nearby river and a massacre of French settlers in 1564.The fort sits on the banks of the nearby Matanzas river. Matanzas means "slaughters" in Spanish.

Construction began in 1740. The structure was largely made from coquina rock. This rock is commonly found along the coastal areas along the Atlantic Ocean and makes a sturdy building material. Construction was completed in 1742. Fort Matanzas was be tested several times but stands today. (Read more on Associated Content.)

Driving the building of the forts  were fears that St. Augustine would be attacked by British forces... From: The St. Augustine Fort Matanzas National Monument