Fodor's Expert Review Musée des Instruments de Musique (MIM)
This four-story building is almost as impressive as the museum it houses. Built in 1899, architect Paul Saintenoy didn't hold back. Its elaborate facade twists its glass and iron into a symphony of Art Nouveau. Inside, it's no less fascinating. If you've ever wanted to know what a gamelan or Tibetan temple bell sounds like, here's your chance. In addition to seeing more than 2,000 instruments, you can listen to most of them via headphones. Head to the rooftop café for fantastic views of the city; also look out for MIM's regular lunchtime concerts—some are even free.