The Border Road

An almost closed bay in the shape of a shell, with the town all round it and two hills guarding either end. La Concha is reckoned among the finest urban beaches in Europe. The town also has one of the highest densities of Michelin stars in the world, but what matters for this route is something else: the language spoken here is the same as at Saint-Jean, across the border, an hour away. The Basques were here before Latin, and the border of 1659 cut them in two without changing them.

A fortified Basque town at the foot of the Roncevaux pass, which for a thousand years has been the last stop before the mountains for pilgrims to Santiago. Tens of thousands still pass through its gate each year. Here the border does not separate: the Basques on both slopes speak the same language, which resembles no other in Europe and was spoken here before Latin arrived.

Every 13 July, the mayors of three French villages in the Barétous valley climb to the boundary stone at Ernaz and hand thirty heifers to the mayors of the Roncal valley. It is compensation for a fight over pasture in 1375, settled by treaty and paid without interruption ever since — the oldest treaty in Europe still in force. The border between states has moved more than once; the agreement between the villages, never.

Ordesa y Monte Perdido is Spain's oldest national park, from 1918, and it is a glacial valley with vertical walls a thousand metres high, in reddish limestone, beneath Monte Perdido — the third summit of the Pyrenees, 3,355 m. It is the Spanish side of the same massif that, on the French side, gives the cirque at Gavarnie. The same rock, two countries, two names.

A glacial amphitheatre four kilometres wide and fifteen hundred metres high, with steps of limestone and a waterfall of 422 metres, the tallest in France. Victor Hugo called it the colosseum of nature. In the wall, at 2,700 metres, is the Brèche de Roland — a gap forty metres wide which legend says was cut by Roland's sword. It is the border: on the other side is Spain.

The most frequently climbed pass in the history of the Tour de France, crossed more than eighty times since 1910, when the first rider to reach the top shouted at the organiser that they were murderers. At the summit stands the statue of Octave Lapize, that rider, put up every summer and taken down in autumn before the snow. In winter it is closed; in summer it is full of cyclists.

An astronomical observatory built on the summit in 1878, for which the materials were carried up on men's backs over twenty years. NASA photographed the Moon from here for the Apollo missions. Today it has a terrace suspended over the drop, a museum and the best sky in France — the area is an international dark-sky reserve. You can sleep up there, in the astronomers' old cells.

In 1278 the bishop of Urgell and the count of Foix failed to agree who ruled these valleys and signed an act by which they ruled them jointly. The act has never been annulled. Today Andorra has two heads of state: the bishop of Urgell and the president of France. It is the last working remnant of the medieval system of unclear borders — a state that exists because the border was never drawn.