But a number of countries offer what’s called a “visa on arrival,” which is exactly what it sounds like: a visa you apply for once you arrive in a given country. According to the Passport Index, an exhaustive resource that tracks passport perks around the world, a U.S. passport gains you visa-free entry to 123 countries (It’s currently tied with Iceland at eighth place in the passport power rankings; the United Arab Emirates is in the top spot.) Learn more about visas on arrival from VisaGuide.World, and always be sure to research up-to-date prerequisites for visiting any country—visa-free, visa on arrival, or otherwise—before you go.