Ok Corral (2)

A pen is a fenced/walled open-air enclosure for holding land animals in captivity, typically for livestock but may also be used for holding other domesticated animals such as pets that are unwanted inside buildings. The term describes types of enclosures that may confine one or many animals. Construction and terminology vary depending on the region of the world, purpose, animal species to be confined, local materials used and tradition. Pen or penning as a verb refers to the act of confining animals in an enclosure.