The Roman Pantheon is arguably the greatest surviving structure from ancient Rome. And not only does it survive, it radiates a vision and elegance that are nothing short of modern in their execution. To stand on his porphyry-inlaid floor and look up into the giant oculus in its dome is to forget completely that you are standing in a super-structure built nearly 2,000 years ago. On paper it is another temple among many dedicated to the pagan gods of Rome. In practice it is a colossal structure topped with the largest unreinforced concrete dome in the world – a feat of engineering that required such painstakingly precision no one has dared to attempt it since. One of the main reasons it remains in such good nick is that is has never fallen out of use. Since the 7th century it has been used as a Christian church, and you can still attend worship there on Sundays. Regardless of when you go, visiting the Pantheon will take you inside one of the most unique and breathtaking buildings on earth.
Visiting the Pantheon: What to See
The gigantic portico of the Roman Pantheon is framed by 16 granite columns, each a single piece of stone measuring 39ft tall and 5ft in diameter. Each weighs 60 tons. As if their scale weren’t enough, every column had to be imported from Egypt via a system of barges and boats greased with untold amounts of slave labor. Modern engineers still haven’t figured out every detail of how people in the first century BC managed to transport the gigantic columns, along with Rome’s famous Egyptian obelisks, over such long distances, and there is a good chance that they never will. In ancient times the portico probably featured bronze relief statues along its roof. This is the same bronze work that some archaeologists believe was stripped for use in Bernini’s baldachin in St. Peter’s Basilica, but the jury is still out.
When we think of ancient Roman architecture the first thing that comes to mind is marble. So you might be surprised to learn that the big innovation of Roman architecture wasn’t with stone work, it was with that most “modern” of building materials – concrete. At its simplest concrete is a mixture of wet ingredients mixed with small pieces of stone (aggregate) for toughness that sets due to a chemical reaction. It has been in use since before the advent of recorded history but the Romans were to first to employ it for large scale, curved, super structures like the Pantheon. Roman concrete (as opposed to modern “Portland” Cement) is a mix of water, lime, and volcanic ash called pozzolana. In order to build a 5,000 ton dome that wouldn’t collapse in on itself, workers had to create coffered pozzolana blocks that all conformed to precise dimensions. Even the tiniest deviation in the shape of a single block would have thrown off the entire dome as they built toward its apex.
Not only did the shapes have to be right, the density of the blocks had to decrease as they went up. If the top of the dome was as heavy or heavier than the base, it would be structurally unsound and eventually fall. In order to work around this the designers used lighter aggregates in their blocks as they got higher so that the blocks near the top of the dome contain pumice and tufa (comparatively light stones) while those near the base contain brick and travertine. 142 feet above the floor the 30-foot oculus opens to the heavens and lets natural light spill in, moving in a reverse sundial effect through the interior during the course of the day. Given that the building has been open to the elements for nearly 2,000 years the floor has held up very well. If you take a close look you’ll see that drainage holes are cut into it allowing rainwater to drain away without puddling on the stone and doing lasting damage.
A Bit of Trivia
Whether the bronze from the portico did or did not go into Bernini’s divine baldachin in St. Peter’s, it definitely went into the making of cannons for the Castel Sant’Angelo and not all Romans were happy about it. A contemporary poem quipped: “What the barbarians did not do, the Barberinis did”. (Barberini was the last name of Pope Urban VIII, who ordered the removal of the bronze.)
You might know that the Renaissance master Rafael is buried in the Pantheon. But less well known is that his fiancé is buried beside him. The story goes that Rafael was engaged to be wed to Maria Bibbiena but put off the marriage for six years (carrying on at least one affair in the meantime) until poor Maria died. It appears that Rafael’s motivations for marriage were basically connections. What poor Maria thought isn’t too hard to infer, either.
For more on Raphael’s rather prolific love life, check out our blog on Raphael’s Mistress.
No one knows why the Pantheon was originally built. That it was a religious building is clear, but who or what was worshiped there remains intriguingly vague. It seems, from contemporary writings, that “Pantheon” may have only been a nickname for the building but what it was actually called and what purpose it was meant to serve is still a matter of conjecture.
The Pantheon was one of the buildings studied by Filippo Brunelleschi when he was was trying to figure out how to construct the massive Dome on the Florence Cathedral.
For more background info before you visit, check out our blog on the Pantheon.
Tips for Visiting the Pantheon
The Pantheon opens every day at 9:00am and closes at 7:30pm every day except Sunday, when it closes at 6:00pm. Mass is celebrated (its official name is the Chiesa Santa Maria ad Martyres) every Saturday at 5:00pm and every Sunday at 10:30pm. It closes for national holidays, midweek holidays at 1:00pm and on January 1st and December 25th. There are no tickets for the Pantheon, it’s a public space.
In recent years, the Pantheon has installed a basic security system at the entrance. Prepare to have your bag checked if you are carrying one, but don’t expect long lines to get in.
The Best Time to Visit the Pantheon
Despite the fact that you could fit a 143ft diameter sphere inside the central atrium, it is notorious full becoming packed with visitors during the high season. Midday and the afternoon are particularly bad times crowd wise. As with most of the famous public works in Rome, the best times to visit the Pantheon are early – right when the doors open at 9:00am, or just before it closes in the evenings. To get the full impact of seeing the dome from the inside try to go on a day with plenty of sunlight, the sight of light pouring down from the glowing oculus is indescribably affecting.
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