Hôtel-Dieu de Tonnerre

Founded in 1293 by Marguerite de Bourgogne, Countess of Tonnerre, the Hôtel-Dieu is one of the best-preserved medieval hospitals in France. Its Grande Salle stretches 96 metres beneath an inverted-ship-hull timber roof; the walls are pierced with twin Gothic lancet windows. In use as a healthcare facility until 1982, it now houses a museum whose treasures include a 15th-century Entombment carved from a single block of white marble, a 1785 meridian line, and the recumbent effigies of its founder and the Marquis de Louvois.