Halle Saint-Pierre is a former 19th-century iron market in Montmartre that now houses one of Paris's most distinctive cultural venues. The space hosts rotating exhibitions of Art Brut and outsider art, alongside a packed calendar of surrealist conferences, literary meetups, and performances. There's a bookshop and café on-site—though note that only sweet options are served on Sundays. The venue closes entirely during August and on major French holidays.