Monaco

Monaco is the world's second-smallest country — a 2.02 square kilometre city-state on the French Riviera wedged between France and the Mediterranean Sea. It is also the densest and one of the wealthiest places on Earth, a principality ruled by the Grimaldi family for over 700 years, famous for its casino, Formula 1 Grand Prix and an unabashed celebration of extreme wealth that makes it a fascinating, if somewhat unreal, destination. The Casino de Monte-Carlo, a Belle Époque masterpiece designed by Charles Garnier (who also designed the Paris Opera), is the centrepiece of the Monte-Carlo district — even if you don't gamble, the interior is extraordinary and the surrounding gardens and hotel exteriors are spectacular. The Palais Princier on the Rock (Le Rocher), the 13th-century castle that is the Grimaldi family home, offers guided tours when the Prince is away. The Cathédrale de Monaco contains the tombs of Grace Kelly and Rainier III. The Musée Océanographique, founded by Albert I and perched on the Rock above the sea, is one of Europe's finest aquariums and oceanographic institutions. The Monaco Grand Prix circuit runs through the streets — walking (or cycling) the route at any time of year gives an appreciation of how impossibly narrow and twisting it is. Monaco is expensive even by Riviera standards, but a day trip from Nice (25 minutes by train) requires no commitment to overnight costs.