Instructions
Pick a spot for your pen. Look for flat ground with good drainage. If it the land is uneven and low, you must level it and install a drainage system.
Add layers of footing to the pen area. Start at the bottom with gravel or stone; end at the top with sand, shredded rubber or mulch. Remember that your horse will work on the top layer, so don't use any hard surfaces or rock.
Determine the size of your pen and the height of your fence. Most horse owners prefer a 60-foot pen. Your fence should be at least 5 feet high, with 6 feet representing the ideal.
Choose the material from which you will construct the fence. Livestock panels are popular and easy to assemble. They also make the pen portable, but this alternative can be pricey since you will need 15 12-foot panels to make a 60-foot pen. Wood costs less, but your construction will be more complicated.
Dig holes for the individual posts if you are using wood. Start in the center of the pen with a measuring tape and mark off a perfect circle. Set the posts between 10 and 12 feet apart.
Install the railing to the posts. A 3-rail fence is adequate, but 5 or 6 rails will be more effective.
Hang a gate on one of the posts; put another post on the opposite side for the latch. Make the gate wide enough to ride your horse through.
How to Build a Round Pen
If you own a horse, you can use a round pen for training and exercising the animal. Your pen should be between 50 and 60 feet in diameter for both you and your horse to be comfortable. You can build it by following these steps.