Round pen connected to arena. Great idea plus it looks really nice. The only think I'd change would be that I'd add another gate on the outside of the round pen.
Horse Riding & Equestrian Arena Maintenance- great info, and I L-O-V-E this arena! sopretty
covered with lighting - could easily be made into an indoor arena later or at least somewhat more sheltered
Building An Arena at Home~Create the perfect space to ride your horse on your own property.
Blanket rack between stalls: Holy mackerel this is insanely clever!
European Country Manor-Horse Farm
Outdoor Riding Arena Plans | ... jpeg horse arena failure http www gestech net horse arena failure htm
Building a horse-riding arena: Thinking outside the rectangle - Features - Horsetalk.co.nz
Beautiful outdoor arena I'd probably add more greenery around the edges to make it more welcoming