Castillo de San Marcos National Monument is in downtown St Augustine Florida, and is one of the best sites I have visited so far. Castillo de San Marcos is actually Spanish for St Mark’s Castle, the oldest masonry fort in the united states. Completed in 1695. I am not going to go into all the great history of this fort, but originally Spanish, then the British took over, then the Spanish then the US, etc. So much history and the tour was so interesting. If you are ever within a few hours of St Augustine, take a day at least, you will not be disappointed.
The fort is actually part of the downtown area, actually part of the Old Town district. Technically the oldest city in the US. Old brick streets, various shops and more places focusing on the history of St Augustine. Just was a lovely day. I am staying in the national forest about 1 hour west, I will be back to see more of this city.