Ferris wheel
A Ferris wheel is a nonbuilding structure
Nonbuilding structure
Nonbuilding structures, also referred to simply as structures, are those not designed for continuous human occupancy. The term is used by architects and structural engineers to distinctly identify structures that are not buildings....

 consisting of a rotating upright wheel with passenger cars (sometimes referred to as gondolas
Gondola (disambiguation)
A gondola is a traditional Venetian rowing boat, best known today for transporting tourists.Gondola may also refer to:-Fixed structures:...

 or capsules) attached to the rim in such a way that as the wheel turns, the cars are kept upright, usually by gravity.

Some of the largest and most modern Ferris wheels have cars mounted on the outside of the rim, and electric motors to independently rotate each car to keep it upright.