Squeezed into just 200 hectares, this principality might be the world’s second-smallest country (the Vatican is smaller), but what it lacks in size it makes up for in attitude. A magnet for high-rollers and hedonists since the early 20th century, it’s also one of the world’s most notorious tax havens (residents pay no income tax). It’s also famous for its annual Formula 1 Grand Prix, held every year in May since 1929.