See the city that could have been. Museum of the Phantom City lets you view visionary designs created by architects and artists throughout history. Walk through the city and see Buckminster Fuller’s Dome over midtown Manhattan, Adolf Loos’s unbuilt Chicago Tribune Tower, or Archigram’s pop-futurist Walking City, all while standing on the projects’ intended sites.

To use: White bursts overlaid on a darkened map of the city indicate the sites of past visions. Tap on the burst to unlock the content for that site. Users can “rate” the futures, and access other features, by tapping at the bottom of the screen.