What is a round pen?

A round pen is a fairly small circular enclosure, usually fifty or sixty feet in diameter, that is used to train horses, usually at liberty.

Round pens are used when working with green or difficult horses. They allow the horse to be kept in a relatively confined space whilst still giving enough distance for the handler to get out of the way if needed.

Some designs are portable and may also be used to corral horses overnight at a trailhead or similar.