Round pen

Traditional designs intended for control of untamed feral horses are made of heavy lumber and up to 8 feet (2.4 m) high, to prevent the animal from jumping out or running through the fence.

Traditional round pens have closely spaced rails that allow foot room for a human to climb out of the pen, but also give the fence great strength and also discourage the animal from seeking escape due to the near-solid appearance of closely spaced rails.

In this design, the bottom section of the fence may be solid to prevent the sand or loose dirt from being pushed out of the pen by the movement of the animal.

The drawback to a bullpen design is that the solid, smooth walls hinder a human's escape from the pen by climbing over the fence if needed.

Most round pens are located outdoors, but due to their relatively small size can easily be enclosed by a roof or a tension fabric building.