Looping

The generic roller coaster vertical loop, also known as a Loop-the-loop, or a Loop-de-loop, where a section of track causes the riders to complete a 360 degree turn, is the most basic of roller coaster inversions. At the top of the loop, riders are completely inverted.
The vertical loop is not a recent roller coaster innovation. Its origins can be traced back to the 1850s when centrifugal railways were built in France and Great Britain. The rides... meer