Santo Domingo

Santo Domingo needs 2 days: the Colonial Zone (a UNESCO World Heritage Site) on one, with the Cathedral of America and the Ozama Fortress, and the Malecón along the Caribbean Sea on the other. December-April is best. It's inexpensive by Caribbean standards. Founded in 1496 by Bartholomew Columbus, it's the oldest European city in mainland America, with the first cathedral, first university and first paved street in the New World, still standing within its colonial old town.