Viejo San Juan, as it's known in Spanish, is the oldest colonial settlement in Puerto Rico, and actually is its own tiny little island. Three bridges unite this small land spit with the larger San Juan city. Surrounded by the Atlantic Ocean and San Juan Bay, it's dominated by a large bluff on the north end, and there you'll find "El Morro," the commanding old fort at the top of colonial Spanish battlements. Viejo San Juan's crooked winding streets are built in the old Spanish style—ladder like, so as you walk them you gradually climb the tall bluff, but without the strain of a direct ascent. That style also puts one side of the street in "sol" and another in "sombra," (sun and shade, respectively) no matter the time of day—another trick Spaniards devised to avoid the scorching heat. San Juaneros always walk in the "sombra." Atmospheric and enchanting, Viejo San Juan is the stuff postcards are made of—vivid blue, yellow, white and pink buildings, cobblestone streets, old porticoes and flower-covered trellises. It is made to wander through, with no particular destination in mind, as you soak up the history and architectural splendor.