There is such a lack of great fighting venues around so here are my ideas

1. a pit in the middle of a wastland or jungle for people to fight in complete with a crowd prop at the top looking down cheering

2. An arena just like the one in the movie Bloodsport complete with a morph to bend the floor complete with crowd

3. a Simple cheering crowd prop in a circle for people that streetfight, you could do real life, fantasy, sci fi and western

4. An arena like the one in the movie Flash Gordon where the floor moved and had retractable spikes

5. a high bridge over spikes, lava or acid similar to Mortal Kombat.

6. A steel cage just like the one on MMA fighting with crowd prop

 

Thanks!