Langres: The Walled Town of Diderot and the Lac de la Liez

Required Activities

• Walk the full 3.6 km circuit of the Langres wall and count off all seven fortified towers and six gates, finishing at the Gallo-Roman gate, then find the stretch from which the Lac de la Liez comes into view below the plateau

• In the Maison des Lumières, find the 18th-century measuring instruments and the celestial mechanics among the science rooms, then hunt down a plate from the Encyclopédie showing a trade you can still name — and afterwards walk the streets of the old town where Diderot grew up, the son of a Langres cutler

• Go into the cathedral of Saint-Mammès and find the two surviving hangings from the eight woven in 1544–1545 after Jean Cousin for cardinal de Givry, on the life of Saint Mammès — of the eight only three are left, and the third is in the Louvre — then step back outside and see how little the classical front of 1760 to 1768 tells you about the 12th-century church behind it

• Walk down to the Lac de la Liez and follow the shore to the head of the dam, then look for where the water is drawn off for the canal de la Marne à la Saône — the lake was dug at the end of the 19th century to keep that canal in water, and swimming and boating came later

• Find Bartholdi's bronze Diderot in the middle of the place Diderot, put up in 1884 for the centenary of his death, and then work out how far it is from there to the cathedral — the town fought hard against honouring an avowed atheist within sight of the church that had made it powerful