Mons has a compact, mostly pedestrianised historic centre that rewards an afternoon of wandering. The Grand-Place and the hilltop Collegiate Church of Sainte-Waudru are the set pieces, but there are quieter corners — Ottoman-era towers, the curious iron monkey at the town hall, and the Mundaneum, a museum that tells the story of the Belgian librarian who tried to index all human knowledge on index cards in the 1890s. The WWI memorials around the city are among the most moving in Belgium.