El Morro, which sits within the San Juan National Historic Site, juts out of San Juan harbor and beckons to cruise ships. Construction of the hulking, six-story fortress started in 1539.

The fort was known as "El Morro," and as the attacks on it multiplied, so too did its defenses. Who Was the Real Cleopatra? Fact or Fiction? The Legend of the QWERTY Keyboard What Does a Cowboy ...