Art 42 Montmartre & Northern Paris

Street art and post-graffiti now have their own dedicated space at this 'anti-museum', with works by Banksy, Bom.K, Miss Van, Swoon and Invader (who's behind the Space Invader motifs on buildings all over Paris), among other boundary-pushing urban artists. Compulsory guided tours, generally lasting 1½ to two hours, lead you through 4000 sq metres of subterranean rooms sheltering some 150 works. Entry's free but you need to reserve tours online (ideally several weeks in advance, although last-minute cancellations can arise).