Langres, 35km south of Chaumont and just as spectacularly situated above the Marne, retains its near-complete encirclement of gateways, towers and ramparts. If you’re just here for an hour or so, the best thing to do is to walk this circuit, with its great views east to the hills of Alsace and southwest across the Plateau de Langres. Don’t miss the St-Ferjeux tower with its beautiful metal sculpture, Air and Dreams. Wandering inside the walls is also rewarding – Renaissance houses and narrow streets give the feel of a place time has left behind, swathed in the mists of southern Champagne.

Langres was home to the eighteenth-century Enlightenment philosopher Diderot for the first sixteen years of his life, and people like to make the point that, were he to return to Langres today, he’d have no trouble finding his way around. The Musée d’Art et Histoire on place du Centenaire near the cathedral, duly devotes a section to Diderot, including his encyclopedias and various other first editions of his works, plus a portrait by Van Loos. The highlight of the museum is the superbly restored Romanesque chapel of St-Didier in the old wing, which houses a fourteenth-century which houses painted ivory Annunciation.