Wheel gymnastics
While being a child, Otto Feick, the son of a blacksmith from Reichenbach, Germany, used to roll down a hill in two wagon tires which inspired him later to invent the wheel gymnastics between 1920-1922. The current wheel gymnastics obtained its final shape in 1974 with the introduction of the PVC coating. Now, it's a competitive sport practiced in Belgium, Denmark, Netherlands, Austria, Switzerland, Japan, and United States of America.