Buildering (also known as edificeering, urban climbing, structuring, skywalking, boulding, or stegophily) describes the act of climbing on the outside of buildings and other artificial structures. The word "buildering", sometimes misspelled bildering, is a portmanteau, combining the word building with the climbing term bouldering. If done without ropes or protection far off the ground, buildering is extremely dangerous. It is often practiced outside legal bounds, and is thus mostly undertaken at night.