Here’s a museum for the techies in your crowd. With a collection that runs from astrolabes to supercomputers, this place is a goldmine for geeks of all shapes and sizes. The goodies are organized into seven categories: scientific instruments, materials, construction, communication, energy, mechanics, and transportation. Learn how the metric system was born, what the first waterwheels looked like, and how the machine age got up to speed. See cyclotrons, gasometers, and microscopes. Probably the most famous item on display is Foucault’s original pendulum, which still gracefully demonstrates the rotation of the Earth, just like it does in Umberto Eco’s eponymous novel. The museum is housed in the ancient abbey of St-Martin-des-Champs.