It doesn't quite look like concrete. My guess would be that it is foam, so that means a children's area like Ariel's Grotto or Thousand Acre Woods.
Here it is! Right BEHIND the castle! [This attachment has been purged. Older attachments are purged from time to time to conserve disk space. Please feel free to repost your image.]
We're going back in March and I sure will be looking at the World differently thank to these games! How many times have I walked over that compass and I promise I don't think I ever noticed it. Yikes.