It’s awfully hard—though not impossible—to find a long network of decently paved roads in most island and tropical countries. Your mountain biking options are somewhat better: mostly uncrowded trails through scenery that will make all of your gearhead friends at home jealous. Here are my on- and off-pavement recommendations. I’m sticking to the Caribbean and Central America because they’re the most accessible. If you're going solo, bring your bike or make sure to figure out where you'll rent one beforehand—most outfitters in these parts only rent rigs to people taking one of their guided tours.