All of those are great ideas! Could also have some without a ring. Could open up more possibilities for locations.

I do like the idea of beaches and outdoor arenas as I’m pretty sure there have been events in those kinda places.

Ideas on the top of my head include a gladiatorial-style arena, a dark alley for street fighting and a small kiddy pool (cause why not?)

Could try traditional mats like you'd see in olympic or scholastic wrestling. Also could try stuff like "oil" or "mud" matches in pools.

All solid options, a rooftop match with something like chain link security fencing or barricades against the skyline could be a good backdrop.

Could also just focus on action falling out of the ring for a smaller change. Wrestling continuing on the floor between ring and audience, back on the ramp, or even all the way back to catering.

For something grittier than pro wrestling, love old warehouses, single rope ringing in the action or something like a barn or corral are other options.

I do like more varied arenas. Doesn't always have to be in a ring after all.

Always been a fan of tribal style setting myself, I feel wrestling works there nicely.
I also like the barn/corral as stated above for a more friendly feeling fight.