The United States National Parks System has over 400 parks, including places of great natural beauty and historic significance. Included in our magnificent parks system is the San Juan National Historic Site. The site includes what remains of the walls which surrounded the City of San Juan, and one of the original gates, La Puerta de San Juan. The site also includes the forts which protected the city from invaders, Castillo San Felipe del Morro, Castillo San Cristóbal, and Fort San Juan de la Cruz. For more information on our visit to the San Juan National Historic Site, and more information about our trip to Puerto Rico, visit our sister site,…