Areana Type Structures

Thinking about maybe building an arena type place out of one of my houses for use in PvP tournaments, pet tournaments, etc but can't come up with anything good. Anyone have any screenshots or locations that I can get a look at?

On Baja, inside the inner mountain umbra desert...there's a place called the collisium (I think I so mis-spelled that). It's about in the middle of that desert anyhoo.

Thanks..I'll run through there and have a look.