In the suburb of Bagneux south of Saumur, hidden in a small courtyard behind a corner cafe, stands one of the largest Neolithic chamber tombs in Europe — roughly 5,500 years old. The structure is a covered gallery of vertical megaliths roofed by four enormous slabs, large enough to stand inside.
The setting is famously incongruous: you pay a small fee at the cafe, walk through a back door, and find yourself in a prehistoric monument behind plastic patio furniture. The juxtaposition is part of the charm. Easy to combine with a visit to the Musée des Blindés a short walk away.