Separating the Iberian Peninsula from the rest of the European continent, the snowcapped Pyrenees have always been a special realm, a source of legend and superstition. To explore the Pyrenees fully—the flora and fauna, the local cuisine, the remote glacial lakes and streams, the Romanesque art in a thousand hermitages—could take a lifetime.

Each of the three autonomous Pyrenean mountain regions that sits between the Mediterranean and the Atlantic is drained by one or more rivers, forming some three dozen valleys, which were all but completely isolated until around the 10th century. Local languages still abound, with Castilian Spanish and Euskera (Basque) in upper Navarra; Aragonese (and its local varieties) in Aragón; and Catalan at the eastern end of the chain from Ribagorça to the Mediterranean.

Throughout history, the Pyrenees were a strategic barrier and stronghold to be reckoned with. The Romans never completely subdued Los Vascones (as Greek historian Strabo [63–21 BC] called the Basques) in the western Pyrenean highlands. Charlemagne lost Roland and his rear guard at Roncesvalles in 778, and his Frankish heirs lost all of Catalonia in 988. Napoléon Bonaparte never completed his conquest of the peninsula, largely because of communications and supply problems posed by the Pyrenees, and Adolf Hitler, whether for geographical or political reasons, decided not to use post–Civil War Spain to launch his African campaign in 1941. A D-Day option to make a landing on the beaches of northern Spain was scrapped because the Pyrenees looked too easily defendable (you can still see the south-facing German bunkers on the southern flanks of the western Pyrenean foothills). Meanwhile, the mountainous barrier provided a path to freedom for downed pilots, Jewish refugees, and POWs fleeing the Nazis, just as it later meant freedom for political refugees running north from the Franco regime.