Cartagena, Colombia, promises an exotic taste of Latin America even if you only have a week or less of vacation time. What you’ll discover: some of the best seafood of your life (so good, Anthony Bourdain counted it among his top picks); colorful streets that ooze Spanish-colonial charm and beg to be photographed; regionally made, artisan keepsakes such as wide-brimmed straw hats and iconic mochila bags; boutique properties so sumptuous and inviting they feel more like a stay at your friend’s historical mansion than a hotel; and day trips to remote islands for snorkeling and seafood straight from the ocean to the grill.