overview opening hours admission programme Reon's Magic Cavern project has a long history, reaching back to the 1970s in Bretagne. The Petřín Magic Cavern opened in 2005. Here you can view 80 paintings in the three-floor building, which Reon transformed into a cavern and a museum dedicated to his dreamland Argondie using numerous original sculptures and many tonnes of plaster. The cavern also features a seating area with jugs of free beverages for visitors. opening hours january—december mon—sun 11:00—19:00 more about opening hours admission basic 100 CZK reduced 50 CZK more about admission Source: reon.cz admission basic 100 CZK reduced 50 CZK opening hours january—december mon—sun 11:00—19:00