Between the 15th and 19th centuries, a series of defensive structures was built at this strategic point in the Caribbean Sea to protect the city and the Bay of San Juan.
英
美
- 公元15世纪至19世纪期间,在加勒比海的战略要地上建起了一系列防御工事用于保护圣胡安城和圣胡安海湾。