[Post updated with official video, thanks misterhonk].
From Prague, a video-mapping show projected on the medieval Astronomical Clock in the city's Old Town Square. Part of a celebration for the 600th anniversary of the clock's construction.
Via the BB Submitterator, Boing Boing reader Treyka sends us the link and says, "I had no idea this was even possible with projector technology!"
Me neither! The dazzling visual show goes on for a full ten minutes.
BB reader Kerray says, "The people who worked on it are themacula.com, duber.cz and michalkotek.com, and the projection itself was done by avmedia.cz. Four months of work, 5000×1200 resolution, 2x Christie 18K HD projectors."
From Wikipedia, this schematic explaining what the various interlocking dials on the Prague Orloj represent.