What is the other part of the arena (further from the cornucopia) like?

The Quarter Quell Arena is basically a clock, 

I can almost see the hands ticking around the twelve-sectioned face of the arena. Each hour begins a new horror, a new Gamemaker weapon, and ends the previous. Lightning, blood rain, fog, monkeys – those are the first four hours on the clock. And at ten, the wave. I don't know what happens in the other seven, but I know Wiress is right. ch.23