The objects in the arena have been charmed to almost defy gravity, floating around, boulders, rocks, etc
At the base level of this arena is just normal ground with vegetation/shrubs/grass and trees, as well as varying size terrain, ranging from a few feet tall, to much taller
Floating high above in the air is small islands, some with greenery and vines hanging down towards the ground, ranging in size and height from the ground, so that even if a person didn't have the power of flight, if they are an adept climber, everything is spaced out enough they could climb as high as possible, as well as utilise some of the smaller floating debree to aid in their climb. Some of the floating islands even have small waterfalls
Between the floating islands and the tall peeks and trees, there are plenty of shadows and places to hide
On two sides of the arena there are 2 automaton birds stationed, currently in "off" mode, they are roughly 6 feet tall.
The arena is open to the sky and elements
On each end of the arena, on top of some large pillars, are pyres, full of fire and wood. The fire that burns within the pyres can not be extinguished, but if the fire is removed from the pyres, it can then be put out.