I wish I knew more of what the purpose of te hole is for but how about setting some prety potted plants in it. I think it would distract from it.
Add a water feature
Frame it up and turn it into a built in cooler
Add a storage bench that you can sit on.
Could you put a fountain on the area, or maybe a small preformed pond?
Park your grill on that spot. Any hot coals are not going to hit the decking.but will hit the cement pad.