World's most photographed spiral staircase at the Vatican Museums. Designed by Giuseppe Momo in The stairs are actually two separate helixes, one leading up and the other leading down, that twist together in a double helix formation.
The Infinite Staircase sculpture titled Umschreibung was designed by Olafur Eliasson. The staircase can be found at the entrance of the KPMG office building in Munich, Germany. Photo taken by Christian Krieglsteiner.