When was the last time you stumbled across a set of rings or monkey bars outside of the gym? Possibly at a park? But what about the rest of your city? Compared to walls, fences, and gates, both rings and bars are extremely rare in the concrete jungle.A climb-up is the name of an iconic parkour skill that is essentially the real-world, urban application of a muscle-up, on a wall, fence, or similar barrier. Along with landing, rolling, and falling,...