A climbing wall is an artificially constructed wall with grips for hands and feet, usually used for indoor climbing

Indoor climbing

Indoor Climbing is an increasingly popular form of rock climbing performed on artificial structures that attempt to mimic the experience of outdoor rock.Competetive indoor climbing is also called sport climbing....

, but sometimes located outdoors as well. Some are brick or wooden constructions, but on most modern walls, the material most often used is a thick multiplex board

Plywood

Plywood is a type of manufactured timber made from thin sheets of wood veneer. It is one of the most widely used wood products. It is flexible, inexpensive, workable, re-usable, and can usually be locally manufactured...

 with holes drilled into it. Recently, manufactured steel and aluminum have also been used. The wall may have places to attach belay ropes, but may also be used to practice lead climbing

Lead climbing

Lead climbing is a climbing technique used to ascend a route. This technique is predominantly used in rock climbing and involves a lead climber attaching themselves to a length of dynamic climbing rope and ascending a route while periodically attaching protection to the face of the route and...

 or bouldering

Bouldering

Bouldering is a style of rock climbing undertaken without a rope and normally limited to very short climbs over a crash pad so that a fall will not result in serious injury. It is typically practiced on large natural boulders or artificial boulders in gyms and outdoor urban areas...

.

Each hole contains a specially formed t-nut to allow modular climbing hold

Climbing hold

A climbing hold is a shaped grip that is usually attached to a climbing wall so climbers can grab or step on it. On most walls, climbing holds are arranged in paths, called routes, by specially trained route setters. Climbing holds come in a large array of sizes and shapes to provide different...

s to be screwed on to the wall.