Gladiatorial arena & seating

I feel like some kind of gladiatorial combat or arena-based competition is not an uncommon scene in a lot of RPG stories, and it'd be great to have some stamps to help build a setting for one. Seating, in particular, would be helpful. I am picturing something like the Coliseum in Rome. (… Actually, come to think of it, a "Roman"-inspired set of buildings and features would be really neat too).