No more bells, time's up.

We were looking for a city 60 miles south west of Paris.

It sits on the left bank of the Eure River, and is known worldwide for its landmark gothic cathedral.

The cathedral shows up in another unlikely place.

It's the setting for one of the levels of play in the latest release of the popular video game -- Halo.

In Halo 3, the challenge is to fend off a variety of nasty alien attackers -- using grenades, rifles, lasers and just about every weapon imaginable.

It's a case of real architecture showing up in a virtual world.

Chris Carney is multiplayer environment lead for Bungie Studios. He designed some of the virtual spaces in HALO3.

Chris Carney reveals the answer to the geo quiz: the city of Chartres in northern France.

The city is famous for its cathedral, considered a gem of gothic architecture.

Carney was once an architecture student and to this day he remembers the tall structure of the building and the blue light filtering through its stained-glass windows.

After he became a videogame designer for Bungie, he remembered the cathedral and used it as the setting for fighting aliens in the game Halo3.