The Leap-The-Dips roller coaster at Lakemont Park, Altoona, Pennsylvania, as photographed by Joseph Nebus in July 2013. The roller coaster is the oldest still-operating one in the world, and is a rare (possibly unique?) surviving example of the side-friction roller coaster. The lack of upstop wheels means the cars can and do fly off the track, but the side boards keep the cars from plummeting. Depicted are four of the dips.