Rome is a city of constant change. It is also a city that has been sacked many times in its long history. The most recent sacking was by the Catholics, which gave us the notion that all of the really good loot would be at the Vatican. So, that's where we went next.
The main building is an imposing structure, surrounded on three sides by a high, more or less U-shaped wall. The top of the wall is a walkway for the escape of the Vatican officials in the event that the Vatican should come under attack - which has happened a couple of times in its history.
The roof of the Vatican, as well as the entire wall, is punctuated with larger-than-life statues of saints. The style was clearly borrowed from the Forums in their glory, and perhaps some of the statues were too.
There is also a monolithic... well, monolith... in the center of the courtyard, and a fountain on either side. I came to think of them as the evil fountains
because it seemed every time we walked past them a big gust of wind would blow up and spray us with near-freezing water. Perhaps it was a Catholic plot for stealth baptisms. The obelisk has been dated to Egypt in the 13th century BC, was swiped by the Romans in the 1st century AD to stand in Nero's Circus, and subsequently swiped by the Catholics. The fountains were actually designed for this spot, by Maderno and Bernini, respectively.
The first place we went was the dome. This is actually the celing in the hallway outside the dome. The 16th century was not exactly a time for subtle minimalism.
Looking up at the center of the dome from the walkway around its edge. Detailed mosaics of saints, angels, and whatnot decorate the interior of the dome.