The front facade, completed in two periods at the end of the 13th and 14th centuries, is highly ornate, to say the least. I wanted to get a symmetrical shot of the front, but never got the opportunity because I needed to stay with our tour. In addition, the crowds in front of the church were large, and my chances of getting a clear shot were pretty low in any event. Here are exterior shots that I did get.
As great as the complexity of the exterior is, the interior's seems even greater. Here is a shot from the sanctuary looking toward the rear of the nave, that features the cathedral's distinctive black and white stone supporting columns.
And here's another shot looking up toward the cathedral's ceiling, including a glimpse of its dome.
Perhaps even more impressive than the stone construction are the inlaid stone floors, that took 200 years to complete.
Keep in mind that these are not painted features. Instead, each is actually comprised of inlaid black or white marble. We were fortunate during our visit as for most of each year the floor is covered and is on display only during the months of September and October.
Most of this floor art is cordoned off to preserve it against wear. That poses problems for photography. First, the interior is typically poorly lit. Second, there are often reflections off the polished surfaces creating glare. And finally I had to try to capture the artwork by shooting at an oblique angle rather than directly perpendicular to the floor's surface. (Complaints, complaints.)
One other shot from the nave: A Michelangelo sculpture of St. Paul.
During our visit our guide took us to one of the side chapels that was especially (perhaps it would be better to say "nearly impossibly") ornate. The chapel was relatively small, and it wasn't possible without a super wide-angle lens--and fewer visitors--to get a better understanding of the room's incredible ornateness. I did attempt to capture the ceiling elements in the following shot.
I was hampered in this shot because I needed to take it from the side of the room rather than from directly underneath the center of the ceiling, as there was a sculpture located in the center of the room. So here is another shot that features more of the walls.
On our way out of the chapel, I took the following shot of that sculpture in the center of the room that included three female nudes. My thought was to convert it into a black and white, with the figures silhouetted against the light from the window.
I didn't quite nail the shot, but I thought it was OK for my not having more time to center the figures in the light.
After the duomo's initial construction the Siena church fathers decided to make the church substantially larger, with the original structure to serve as just a side nave. However, after construction in the first part of the 14th century of one side wall for the proposed main nave, the city was decimated by the plague in 1348 and lost more than a third of its population. The city never really recovered and the plans for a more massive duomo were abandoned.