Santa Maria in Trastaveri. One of the very oldest churches in Rome, it was on the other side of the river (hence the word Trastaveri) and you had to get to it by going over a particular bridge. That bridge is in ruins now, and you can see the pilings and footings for it, but the church is still there. It was dedicated to St. Mary, whose face adorns the arch way over the sanctuary. Much of the decoration is new, that "Oh MY" ceiling you see in the below picture is quite modern, no more than a hundred years old. Before that you would have seen a timber ceiling that would have been pretty much blackened by centuries of candle soot. Fortunately, the frescoes have been restored to original, and the mosaics of course, are still as bright as day.
Occasionally the light comes out, and all that gold leaf just pops! The church is "Romanesque", which is to say, there are two aisles formed by columns, a central clerestory, and a large apse, or half dome in back. Look closely at the pillars...they have been robbed from some antique roman temple, even the scrollwork at the top of the pillars are different from column to column. Its quite possible, even probable, that these columns are on their original bases, that the church was built around them. And there would also probably be plenty of pagan foundations, say, a mitraeum, or some such place of worship because the early church liked to build on the old places. A sacred site is a sacred site...and besides, it helps if the foundations are solid.
Above is the right hand ambulatory (aisle)...leading to the south chapel. The south chapel is usually the prettiest since the sun really perks it up. The north chapels in all these churches often hold the oldest artwork since there is no sun to fade it. They often stuck bell towers over the north chapels since they tended to be cold and uncomfortable anyways. This auld kirk is nae exception.
From the outside, you can clearly see the old architecture. Chances are most of what you are looking at has been fixed or replaced sometime in the last fifteen hundred years, but the lines are just as they were laid down when this church was built...in 500 AD. Of real interest to me is the roof...doesn't it look like the roof of a greek temple? It should. It is.
And this is a closeup of the old east wall. The sun has faded the old paintings almost to invisibility, but hey, they are nearly a thousand years old, so they can be forgiven for being a little faded!
Above are the popes, starting from Peter. All in a row. There are a lot of them! I like the windows up there...they are not stained glass...but rather, thin sheets of amythyst.
The woodwork on the portico which encloses the garden courtyard.
The little courtyard. With a few tourists....
The base of a rather larger pillar. Don't quite know how old it is, but there are soldiers in chain mail carved midway along it. There is a lot of pagan influences on this pillar. It sits pretty much above the tomb where St. Paul is buried.
A light shines on the current Pope. 
A good shot of the ceiling. Beatifully coffered. Not ancient....likely no more than a couple hundred years old.
The pillars are all robbed from existing Pagan Roman temples, probably from Rome, but some must have come come from Hadrian's Villa.
The apse. All gold mosaic tiles. 
