Andorra

Andorra is what happens when two medieval powers can't agree on who owns a patch of mountains, so they just share it for 700 years. This microstate wedged between France and Spain in the Pyrenees has two heads of state - the President of France and the Bishop of Urgell in Spain - making it the only country on Earth co-ruled by a foreign president and a foreign bishop. Neither of them lives there.

Despite being smaller than most national parks, Andorra punches well above its weight. In winter it transforms into one of Europe's best ski destinations, with Grandvalira ranking among the largest ski areas in southern Europe. In summer the valleys fill with hikers. Year-round, the capital Andorra la Vella draws shoppers from France and Spain with its tax-free prices. It has no airport, no railway, and no military - but it does have more Romanesque churches per square kilometer than almost anywhere, thermal spas carved into mountainsides, and some of the cleanest air on the continent.