The Col de la Bonette is the high-altitude trophy of the Alps, and it is worth being clear about the statistics. The pass itself is at 2,715 metres, but a loop road branches off to circle the Cime de la Bonette at 2,802 metres, making it the highest paved through road in Europe, or so it is usually claimed. The road was built largely for military reasons in the 1930s, when France worried about its Italian border, and finished in its present form around 1960. Up here, on the border of the Mercantour National Park, the landscape is bare scree and rock, with patches of snow lingering into July, and nothing grows taller than a lichen.
From Jausiers in the north, the road climbs a long valley through larch forest, then opens above the tree line in an enormous bowl, with long, steady hairpins climbing the slope. The surface is generally good, but frost damage and loose gravel at the edges are common, and in places the road narrows. The pass is open from about June to October, and often closes at the first heavy snow, so do check. The descent toward Saint-Étienne-de-Tinée on the south side runs through the old barracks of Restefond, abandoned stone buildings that have been slowly crumbling since the Second World War, and then down a deep, wild valley.
At this altitude the air is thin, the sun fierce and the temperature can be ten degrees colder than in the valley, with fierce wind. Bring windproof layers and gloves even in August. Marmots and chamois are visible if you stop quietly, and ibex have been reintroduced in the area. The views from the summit loop are extensive: peaks stretching toward Italy and, on a clear day, the Mediterranean haze beyond.
Jausiers on the northern side and Saint-Étienne-de-Tinée on the southern side both have pumps, and Embrun, about thirty-seven kilometres away, is the nearest larger town. A small stand sometimes sells drinks at the top in season, but don't count on it. Go early, avoid afternoon storms, and take the loop to the very top, because the point of the exercise is to stand somewhere that most Alpine roads never reach.