Question: On which bay is Castillo de San Marcos located?
Answer: Matanzas Bay in St. Augustine
The Castillo de San Marcos, located on the western shore of Matanzas Bay, is the oldest masonry fort in the continental U.S. It is a large Spanish stone fortress built to protect and defend Spain’s claims in the New World. The national monument is more than 327 years old and is the oldest structure in St. Augustine.
