The Pantheon in Rome isn’t your average ancient temple – it’s a mind-blowing masterpiece of Roman brilliance and one of the best-preserved structures from those ancient glory days. Despite its fame, many people are clueless about its rich history and architecture. So, how much do you really know about this UNESCO-listed architectural marvel? Brace yourself for some jaw-dropping Pantheon facts that will absolutely blow your mind.
Today, it stands as a striking reminder of the architecture of the great Roman Empire, making it one of the city’s top attractions.
17 Fascinating facts about the Pantheon that will amaze you!
1. What is the Pantheon?
The Pantheon might sound straight out of Greek mythology, and that’s because it does have Greek roots. It’s a combination of Greek words – “pan” meaning “all”, and “theon” signifying “gods.” So, when you put them together, you’ve got a fancy name for a place dedicated to all gods.
Originally it was believed to serve as a temple honouring the Ancient Roman gods. However, there is a bit of a question mark hanging over this because nobody’s quite certain which gods were honoured here. Perhaps one day historians will crack the code and reveal the truth.
2. Built three times
What you see now is not the original building. According to the legend of the first Pantheon, this was the site where Rome’s founder, Romulus (one of the sons of a human mother and the god of war, Mars), ascended to heaven.
Let us tell you a tale of three constructions. The Pantheon wasn’t just built once and left alone to enjoy its glory. The temple you see today is actually the third building constructed on the same site.
FIRST VERSION
Most historians claim that Marcus Agrippa, a Roman general and architect who was the son-in-law of the Roman emperor Augustus, erected the first structure between 27 and 25 BC. This wooden building only lasted about 100 years and burned to the ground in AD 80.
SECOND VERSION
The Roman emperor Domitian took a second shot, but it was also a classic fire victim and was wiped out in AD 110. Jupiter (Zeus) controlled lightning; it would likely signify he was unhappy with it or the Romans, in general. At that time, these two incidents were very bad omens for Rome during an otherwise prosperous time. But, as they say, the third time’s a charm, right?
THIRD, CURRENT VERSION
The recent evidence suggests that the emperor Trajan started the construction of a third, present version of the building. The version we can see today is the result of the radical reconstruction by Hadrian probably between 118 – 128 AD. Its construction date is, however, uncertain because he chose not to inscribe it. All we know is that Hadrian was passionate about architecture and used new engineering techniques. And boy, did he nail it!
3. Who designed it?
Emperors wanted something grand, and for that, they couldn’t just draw a few sketches and hope for the best, right? Sadly, due to a lack of written records, nobody knows for sure who was the brain behind this beauty.
Many historians believe Trajan’s architect, Apollodorus of Damascus, is the obvious candidate. But this is only speculation because Hadrian executed this famous architect a few years after he became emperor. Why, you may ask? It was because of some argument about the temple design they had before.
4. The inscription
The only remains from the original temple.
Before you step inside, don’t overlook the inscription at the entrance. This fine print is the original inscription to Marcus Agrippa (a general who built the Pantheon number 1). Why, do you ask? Because while the emperor Hadrian commissioned the rebuilding of the temple for the third time, he didn’t want to put his name on the structure he rebuilt.
What does this writing on the portico mean? Well, “M.AGRIPPA.L.F.COS.TERTIUM.FECIT” it’s in Latin, and it roughly translates as Marcus Agrippa, son of Lucio, made (this building) when consul for the third time’’.
5. Columns
Now, let’s talk about the impressive Corinthian columns from the Pantheon’s portico. These 16 columns, which support the arcade with the inscription, came from a Roman quarry in eastern Egypt. Each is 11.9 m (39 ft) tall and 1.5 m (4 ft 11 in) in diameter. They are from one solid piece of stone and weigh an unbelievable 60 tons each!
A LONG JOURNEY
Imagine the long journey of these massive columns, which they had to take to become part of this building. First, they would have to drag them 100 km from Mons Claudianus quarry to the Nile River on wooden sledges. From there, they would float them down the Nile when the water level was high during the spring floods. After that, they would transport them to vessels, which would cross the Mediterranean Sea and eventually end in the Roman port of Ostia near Rome. From there, they would have to transfer them back on the flatboat and pull up the Tiber River to Rome. Once they got them to land near the Mausoleum of Augustus, they still would need to drag them about 700 m away. Impressed yet? So, next time you are here, take a moment to appreciate these massive columns around you.
FUN FACT:
According to a local legend, touching the central column can bring good luck and heal a minor physical illness.
6. A religious chameleon of Rome
One of the most fascinating Pantheon facts is its survival. You might be asking what saved it from destruction when the other ancient Roman sites are today in ruins. The answer is, in fact, very simple.
The Pagan temple has remained perfectly intact for almost 2,000 years because it decided to switch teams. It became a Christian church in AD 609 and began its journey as the Church of Santa Maria Rotonda. Since then, the Church of St Mary and the Martyrs have been rocking these vibes for 1415 years.
DID YOU KNOW?
This was the first transformed Pagan temple into a church. The building exists in its original form, apart from a few things which disappeared over time.
7. Donkey’s ears
One of the little-known Pantheon facts is that this Roman temple once had bell towers. During the Middle Ages, Pope Urban VIII decided to add two bell towers to the structure. Why? The head of the Catholic Church and the Papal state wanted to give this building more of a church-like look.
Here is an interesting detail: They no longer grace the skyline today because of the negative reactions from the public. The bell towers on either side of the Pantheon’s facade were stylistically different from the rest of the building. Soon, people began calling them donkey’s ears. That’s why they removed them in the late 19th century.
8. Bronze doors
When you step inside, don’t overlook its massive double doors at the front entrance. They are 4.45 m (14.6 ft) wide, 7.53 m (24.7 ft) high and weigh a whopping 20 tonnes each.
Even though they are very heavy, they are well-balanced and easy to open.
And here is a fascinating secret: These monumental bronze doors aren’t just an ordinary entrance but the oldest doors in Rome. For many years, historians thought they were a 15th-century replacement of the original gate. Mainly because many architects believed they were too small for the door frames. But recent analysis confirmed they are original.
Not only is this ancient Roman gate original, but it is also the only remaining door of its kind in its original location. You see, back in the day, it was usual practice to repurpose ancient Roman doors. But these have remained here from the time of the construction.
FUN FACT:
Did you know the Pantheon door is one of the only two doors in the world with a 2,000-year-old lock still in operation?
9. Bronze to Lead
Here’s the fun twist: The Pantheon’s massive dome once sparkled in the sunlight. However, in July 663, the Byzantine king Constans II nicked most of the bronze and took it away to Constantinople.
And according to a local legend, Pope Urban VIII completed the job over a millennium later, in 1625. This pope, who belonged to the Barberini family, ordered the bronze ceiling of the Pantheon’s portico to be melted down. Why did he do that? To construct cannons for the fortification of Castle Sant’ Angelo in the Vatican and other projects around Rome. Since then, there has been a saying: “What the barbarians did not do, the Barberini did”. This phrase refers to the barbarians who sacked Rome and took most of its wealth.
The Pantheon facts: Some even say Bernini used bronze for his famous baldachin, which lies above the altar of St. Peter’s Basilica.
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10. A geometric wonder
Romans inherited the Greek standards of symmetry, harmony and space.
This wasn’t just another Pagan temple; this architectural marvel made other buildings green with envy. This former Roman place of worship is, in fact, a geometric wonder with perfect dimensions.
Here is something cool: Did you know that you could fit ideally a sphere 43.3 m (142 ft) in diameter inside the Pantheon? These perfect dimensions would touch the ceiling, floor and walls. It’s because the height of the floor to the oculus and also the diameter of the round interior are exactly the same.
11. Record-breaking dome
The Pantheon’s dome is the most remarkable feature. Why, do you ask? Well, it’s because this 1,899-year-old dome was the largest in the world for 1,300 years. It passed the title to the Florence Cathedral only in the 15th century. Brunelleschi built the dome for the Duomo with an interior diameter of 45.5 (149 ft) after studying the Pantheon for inspiration. Today, the Singapore National Stadium holds the record of the largest dome in the world. Nowadays, it holds the 15th place.
The Pantheon held the record until Brunelleschi designed an impressive dome crowning the Florence Cathedral in the 15th century.
Want another record? The dome of the Pantheon is still the largest unsupported concrete dome in the world. This architectural masterpiece is a true work of genius, made of concrete that does not have a frame to stand on. If this doesn’t impress you, then nothing will.
12. A work of genius
The dome weighs 4,535 tonnes.
Now, let’s talk a little about the building materials of the dome. The Pantheon’s dome uses a genius construction system. The Roman engineers lighted the dome as much as possible. The thickness of the dome progressively decreases from 6.4 metres at the base to 1.2 m (3.9 ft) around the oculus. Archaeologists also found out they used lighter and lighter materials in the cement the higher up they got.
The concrete of the dome’s lower section contains travertine, then terracotta tiles. At the very top, they used tufa and other porous light stones. And here is where it gets interesting: at the very top, where the dome would be the weakest and vulnerable to collapse, they lightened the load with the central hole. Fancy, right? That’s why it still stands tall and proud almost after 2,000 years.
HOW DID THEY DO IT?
Nobody knows how the Romans laid the concrete. Some theories propose the use of scaffolding, while others suggest they filled the entire building with sand from Ostia. Others are under the impression that they filled it with earth mixed with gold and coins. Once they finished the work on the dome, they told the Romans to take away the soil and keep the gold coins. But hey, whatever they did, they nailed it, didn’t they?
13. The ceiling and its hole in the dome
The ceiling of the dome is another curiosity. Once you look up, you will spot the coffered ceiling and the oculus 7.8 m in diameter. This hole in the dome is the most impressive thing in the ceiling. Together with the doors, they are the only sources of light and ventilation.
Here is where it gets juicy: the oculus at the top of the dome is never covered, and rain and snow occasionally fall through it on the floor. So what happens when it rains?
The Romans were very clever; they equipped the interior floor with a drainage system. When you look down onto the floor, you can see that the floor just gently slopes to the sides. That’s why the interior remains relatively dry even during the heavy rainfall. According to our guide, the sloped marble floor has an incline of about 30 cm (12 in). That allows rainfall to run off after it comes in.
COFFERED CEILING
But there is something else interesting about the ceiling. The coffered ceiling would have been decorated with bronze decorations (they say rosettes). But Pope Urban VIII decided to strip them away. He used the materials for other things, including the cannons and the Bernini’s canopy over the altarpiece of St. Peter’s Basilica.
14. Sundial effect
As you already know, the oculus in the centre of the dome is the main source of light. When you are inside on a sunny day, you can see a large disc of light. Throughout the day, the ray of light that enters through the hole moves around the space.
Here is a juicy part: Did you know the Pantheon in Rome is like a solar temple? There is a clever lighting trick, which you can see every year on April 21, the founding date of Rome. At midday, the sunlight fills the entrance, with light coming from the inside of the temple. This is when the emperor would stand at the entrance surrounded by light. Because of this effect, the Romans would raise their emperor to the level of the god on earth.
15. The final resting place for the kings and artists
The Pantheon facts: Did you know that it has served as a significant burial site since the Renaissance period?
Yes, that’s right, it’s the final resting site for some pretty important figures. We’ve got here the burial place of Vittorio Emmanuele II – he was the first king of a united Italy. There is also a tomb of his son, Umberto I, who rests in peace, alongside his wife, Queen Margarita of Savoy. Margarita is the one who actually gave her name to the local delicacy in Naples – Margarita Pizza. Along those buried, there are also famous painters, including Raphael. He was one of the greatest painters of all history but died at a young age when he was only 37.
The tomb of Raphael
16. Inspired others
It has influenced numerous architects and also designers. Michelangelo said it was the design of angels, not of man. When he worked on the dome of St Peter’s Basilica, he also took his inspiration from this structure.
This unique building also inspired Brunelleschi’s dome of Santa Maria del Fiore in Florence and countless architects in Western architecture. Other famous buildings modelled after it are the Pantheon in Paris and the U.S. Capitol in Washington. And let’s not forget about the Jefferson Memorial and the National Gallery of Art, also in Washington.
17. The area in the past
The Pantheon as we know it today lies on the beautiful Piazza della Rotonda, but it was not always like that. Originally the area wasn’t so open. A large fountain did not exist, and the obelisk of Ramses II was also missing. Pope Pius VII ordered the demolition of filthy shops, inns, and taverns. He also removed smelly stalls with birds and cages on display that filled the square with filth and odours. Later, Pope Pius IX banned vendors and demolished buildings close by.
And here is where it gets interesting: The ground was much lower during the Roman period. Imagine walking up a large row of marble steps to get inside this Pagan temple. There were also two massive statues of Emperor Augustus and Marcus Agrippa – one on each side of the main entrance. Sadly, we cannot see the stairs now because they are under the square.
Did you know there were once the long walls of the courtyard on all three sides leading up to the Pantheon? There was even a memorial arch called the Arch of Piety in front of the building. Moreover, you can also see the remains of a temple dedicated to Neptune (connected to the back of the structure).
Useful information
- OPENING TIMES: The Pantheon in Rome is open for tourists daily, except on 15th August 2025, 25th December 2025 and 1st January 2026. It opens at 9 AM, and the last entry is at 6.45 PM as of March 2025. Remember that you cannot explore it during masses – on Saturday at 5 PM and during holidays at 10.30 AM).
- ADMISSION FEE: Don’t forget that from 3 July 2023, you must buy entry tickets to visit it. The entry tickets for adults start from €5, and EU citizens between 18 and 25 pay €2 as of March 2025. Under 18, worshippers and residents of Rome may visit for free, but they still need to get a ticket.
- The nearest metro station is Barberini (Line A) – it’s about 700 m away.
TIP:
Did you know that you can visit it for free on the first Sunday of each month?
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Last updated: 26/03/2025