The real world meets virtual game-play in today's geo quiz.

Our mystery location is in northern France.

It's a city known for its cathedral.

In fact, the cathedral is one of UNESCO's World Heritage Sites.

The building's considered a gem of gothic architecture.

To put it in layman's terms, it's way cool.

So cool, that it shows up on the popular video game Halo-3.

The guy who designed the game was once an architecture student, and a fan of the cathedral.

With its vaulted ceiling, almost 120 feet high, and the characteristic blue light filtering through stained-glass windows, the cathedral is a sight to see and experience.

Where is it?

Tell you what, we'll let you hear the bells from the cathedral's tall spires.

They will "ring in" the answer to our geo quiz.