Rome's Vatican City has a population of only 550 people and a landmass of just over 100 acres, which makes it the world's smallest independent state, but its influence is extraordinary. Burt takes viewers on a unique tour of the city and its history. There are some amazing images from the ceiling of St. Peter's Basilica as well as a look at St. Peter's Tomb below. We see the Sistine Chapel in close-up and visit the Vatican's 500-year-old mosaic studio.