A climber scaling the outside of a built object may be listed as an event in cases where its occurrence is highly exceptional, particularly when the structure is very tall or presents a challenging climb, to be attempted only by daredevils or expert climbers. This applies especially to skyscrapers, supertall buildings, and towers, which tend to attract such feats. The climber must reach one of the highest roofs of the structure, if not the actual summit, for the climb to be counted.

The event is an exceptional ascent of the exterior. Reaching one of the highest roofs meets the stated endpoint even if the climber does not reach the absolute summit.

The challenge concerns the climb on the object's outside. Ordinary movement inside the building or routine access to a lower exterior level does not have that combination of exceptional ascent and high-roof endpoint.