2,200 lbs of salt

motoi yamamoto uses the ubiquitous white mineral to design unfathomably intricate--and deeply personal--floor sculptures.

Yamamoto's latest labyrinth creeps out from a brick tunnel at the Fondation Espace Ecureuil, a gallery in France. He made it -- as he makes all these installations -- by sprinkling salt on the floor through a plastic bottle used for machine oil, starting at the back of the tunnel, then moving forward to avoid stepping on the designs he's already drawn. The whole thing took 50 hours over the course of five days and a whopping 2,200 pounds of salt.

Sanke Peter parish in Cologne

The story behind Yamamoto's salt sculptures is sweet and sad. His sister died of brain cancer more than a decade ago. To honor her memory, he began sketching with salt -- in Japan, a traditional symbol for purification and mourning. The meandering patterns are meant to convey a sense of eternity.