See The Parts Of The Vatican That Are Off Limits To Tourists

This week the Vatican's papal conclave began the process of choosing the next spiritual leader of 1.18 billion Catholics worldwide.

The majority of the 108-acre country — including towers, apartments, restoration labs, tombs and secret archives — is off-limits without a Vatican City passport.

For a rare look inside the Holy See, we pulled up exclusive videos by National Geographic and History Channel.