[Az-Geocaching] World's biggest cache?

Not in AZ, but in germany - uses an entire underground room for the
container, which is approx. 15 cubic meters in size.

http://www.geocaching.com/seek/cache_details.aspx?wp=GCJD8G

If you can't read German, an English translation is here:

http://www.newvikings.com/geocaching/theunder.htm

Andy