Andorra is a very tiny country on the slopes of the Pyrenees Mountains on the border of France and Spain. Luckily, it's on the sunny side of the mountains.
Tradition says that Charlemagne granted Andorra independence in 806 for their help battling the Moors. The French and Spanish apparently respected that (and the Andorrans) enough to cooperate and share the task of looking out for Andorra. They started this cooperative task in 1278, and apparently continue to this day.
Andorra on Wikipedia