How Has the Pantheon Survived So Well for Nearly 2,000 Years?

The Roman Forum is a field of ruins, the Baths of Caracalla have lost their roofs, and even the Colosseum survives only in part. But then there’s the Pantheon. Nearly 2,000 years old, yet still standing almost exactly as the Romans built it.

So how did the Pantheon survive so well? 

Was It Simply Better Built? 

The Pantheon began life as a Roman temple. Its name comes from the Greek words for pan (“all”) and theos (“gods”), although historians still debate whether it was ever truly dedicated to all the Roman deities. 

The original temple was built by Marcus Agrippa around 27 BC, but burned down in AD 80. Emperor Domitian rebuilt it, only for lightning to strike again a few decades later. The Pantheon we see today dates to the reign of Emperor Hadrian, who rebuilt it around AD 125. Yet he deliberately kept Agrippa’s name across the front, honouring the man who had built the original temple rather than replacing it with his own.

The result was one of the boldest feats of Roman engineering. 

Its vast concrete dome still spans the rotunda nearly two millennia later and remains the largest unreinforced concrete dome ever built. To make that possible, Roman engineers cleverly made the concrete lighter as the dome rises towards the oculus, reducing its weight while allowing such an enormous structure to support itself.

But impressive engineering alone doesn’t explain everything.

The Romans built plenty of masterpieces. Trajan’s Markets climbed several storeys into the Quirinal Hill, while the Baths of Caracalla supplied enormous pools, heated rooms, fountains, and one of the largest bathing complexes the empire had ever seen. Both were extraordinary achievements, yet both eventually became ruins. 

So what made the Pantheon different? 

From Pagan Temple to Christian Church

The real answer lies not just in how it was built, but in what happened over the centuries that followed. Unlike so many monuments of ancient Rome, the Pantheon never fell out of use.

Exactly how it survived the turbulent 5th and 6th centuries following the fall of the Western Roman Empire isn’t entirely clear. Rome declined dramatically during this period, and countless ancient buildings were abandoned, damaged, or stripped of their marble and metal for use elsewhere. 

What we do know is that by the beginning of the 7th century, the Pantheon was still standing, its enormous rotunda protected by the same dome the Romans had built centuries earlier. While many ancient temples had already fallen into ruin, this one was ready for a second life.

That moment came in AD 609. The Byzantine emperor Phocas gave the Pantheon to Pope Boniface IV, who converted it into the church of Santa Maria ad Martyres. To mark the occasion, the relics of numerous Christian martyrs were brought here from Rome’s catacombs and placed beneath the new altar. Today, turning a Roman temple into a Christian church might feel controversial. Yet that very decision became the Pantheon’s greatest stroke of luck. 

People continued coming here. Religious services filled the rotunda, the building remained part of the life of the city, and there was every reason to repair and maintain it instead of letting it slowly fall into ruin. 

Fast-forward more than 1,400 years, and the Pantheon is still a working church.

Preserved… But Not Untouched

That doesn’t mean the Pantheon escaped the centuries without a scratch. 

Parts of the building were repaired, altered, replaced, and stripped of valuable materials over time. During the Middle Ages, a small bell tower rose above the roof, while in the 17th century two bell towers - often attributed to Bernini - were added to the front of the building. Romans disliked them so much they quickly nicknamed them the “donkey ears”, and they were removed again in the 19th century. 

The most notorious episode, however, came in the 17th century, when Pope Urban VIII ordered the bronze above the portico to be removed. Much of it was melted down for cannons at Castel Sant’Angelo, while tradition also links the material to Bernini’s enormous baldachin inside St. Peter’s Basilica. A famous Roman saying later summed up the outrage: “What the barbarians did not do, the Barberini did.”

Rome’s Greatest Survivor

Roman engineering gave the Pantheon an extraordinary start, but engineering alone couldn’t guarantee two thousand years of survival. What really made the difference came centuries later, when its original purpose disappeared and the building found another one. 

A Roman temple became a Christian church, pagan ritual gave way to Christian worship, new generations moved into an ancient space, and a monument that might otherwise have slipped into abandonment stayed part of everyday life in Rome. 

That’s why, nearly 2,000 years after Hadrian completed it, you can still stand beneath the same vast dome the Romans built.

Want to hear the Pantheon’s full story? Our guided Pantheon tour brings nearly two millennia of history to life, from its remarkable engineering and hidden details to the fascinating twists of fate that helped this ancient monument survive.