Night climbing is a term used, principally at the Oxford and Cambridge universities in England, to describe the sport of climbing up the walls of colleges and public buildings, and exploring the rooftops. This activity is frowned on by college authorities, so it is mainly done under cover of darkness, to avoid detection.[1]
The sport is a subset of buildering, or urban climbing, and is distinguished by the fact that it is usually carried out nocturnally by university students.
The original term for this activity was "roof climbing". The alternative term "night climbing" was introduced in the late 1930s, and has become the standard term.