And just like that, it's Mark W's turn! He guessed correctly, and the only info I'll release is that this wonder is in Central Kentucky. There's more out there to discover than just what's inside the DBNF borders.
I am posting the following with a specific request. If you know the answer to this hidden treasure, pm me. I won't disclose it's location beyond general region on this thread. We have to keep a few secrets, right?