San Juan

With walls rising more than 150 feet above the Caribbean, Castillo de San Cristóbal is San Juan’s second imposing Spanish built fort after El Morro, to which it is connected by a half-mile walkway. Covering 27 acres of land, the fort nearly wraps around the city. Construction was completed in 1783; the stone walls served as a gate into and out of Old San Juan until it was partly demolished in 1897 to ease the flow of traffic in and out of the city. A highlight for most is seeing the Garita del Diablo (the Devil's Sentry Box), which is part of a famous Puerto Rican legend that says the devil himself would snatch away sentinels at this post at the edge of the sea. The U.S. National Park Service maintains the site.