(side note - I really don't like this "old thread warning" idea! I'd rather continue a discussion where good points have already been made than make people repeat themselves!)
We're looking at building a round pen, and have two spots on our yard that could work - one would give us an area big enough for a 35' round pen, the other could be up to 60'. I'd prefer NOT to use the larger area since eventually we'd like to build a barn in that area. I've read some conflicting things about the size... some people seem to think 35' would be ok, others think that anything less than 50' is just way too small. I would be working my 14.2 h Arab x mare in it. (Though eventually we're hoping to buy another horse for my husband and it would probably be bigger than my petite little mare!)
Anyway, basically I'm just wondering what other (more experienced) people's opinions are - should we sacrifice the possible barn spot for the bigger pen, or stick with the 35'?