Years ahead of its time, this small but uniquely conceived house was built in 1924 by celebrated Utrecht designer Gerrit Rietveld. He'd be amazed to find that it's now a Unesco-recognised monument. Visiting feels like walking into a 3D Piet Mondrian abstract, and things get especially interesting when the walls start to move. To see a contextualising video, arrive 20 minutes before your assigned tour time (booking ahead is mandatory; an eight-language audio guide is included). Book as far ahead as possible: space constraints limit tours to a maximum of 12 visitors per hour. The ticket is also valid for the Centraal Museum, which displays many of Rietveld's trademark chairs. If you start the day at the Centraal Museum they'll give you a map and lend you a bicycle for the 1.8km ride, but you need to return it by 4.45pm. By bus take route 8 to de Hoogstraat from central stops Neude or Janskerkhof.