A visit to Sulphur Springs, which is dubbed the world's only drive-in volcano, is one of the most unusual excursions you can make in the Caribbean. You'll smell the rotten-egg stench of sulfur and see steam rising around the dormant volcano's crater upon arrival. (Don't worry: The last time the volcano erupted was two centuries ago.) Locals claim that soaking in the mud baths then rinsing off with a dip in the hot springs will rejuvenate your skin and relieve mosquito bites and minor skin problems. Be sure to take a before-and-after selfie to determine whether you look younger after the experience.