Castillo De San Marcos is one of the oldest forts built by colonizers in the United states. It was originally built in 1672 by the Spanish. By this time the Spanish had already established a thriving settlement in St. Augustine. The fort was ordered by Governor Francisco de la Guerra y de la Vega after the city was raided and damaged by English Privateers. The Privateers also completely destroyed the previous wooden fort. This new fort was made with stone to create a stronger base for the Spanish in St. Augustine and was finally completed in 1695.
In 1763 Britain gained control of the fort and Florida through the Treaty of Paris. While under British control the fort was renamed Fort St. Mark. It was transferred back to the Spanish in 1783. It officially became part of the United States of America in 1821 and renamed Fort Marion. The Fort was officially declared a national monument in 1924 and was officially decommissioned from military use in 1933. In 1942 congress restored the original Castillo De San Marcos name to fort.
Today guests can visit Castillo De San Marcos everyday of the year with the exception of Thanksgiving Day and Christmas Day. The park is open from 9 am to 5pm. The entrance fee is fifteen dollars for adults which is valid the next 7 days. Children 15 and younger have free admission as long as they are accompanied by an adult. Guests driving cars should be aware that parking costs $2.50 per hour. The fort is mostly a self guided tour, but the fort also holds occasional events throughout the year. These include re-enactments, firing cannons at night, and so much more. The website's calendar is the best source to learn about these events and when they are happening.