Having lived in Rome for two years (1996/97) I developed the habit of visiting the Pantheon regularly. In a city filled with remarkable monuments, it became one of the places I returned to most often. It’s always a wow moment when entering the busy Piazza della Rotonda and seeing this colossal building right in front of you. I would spend time beneath the huge dome contemplating the continuity of human civilisation, often sitting on the floor before being moved on by an attendant. Despite the constant activity outside, the interior always felt calm and majestic and refreshingly cool, even in the hot summer months.
The Pantheon as we see it today was constructed during the reign of Emperor Hadrian around 118–125 CE, replacing an earlier temple built by Marcus Agrippa in 27 BCE. Hadrian chose to retain Agrippa’s original inscription above the entrance — M·AGRIPPA·L·F·COS·TERTIVM·FECIT, meaning “Marcus Agrippa, son of Lucius, consul for the third time, made this.” It is a reminder of the Roman tendency to honour earlier achievements and maintain continuity with the past.
Originally dedicated as a temple to all the gods of Rome, the Pantheon is now recognised as one of the greatest surviving monuments of ancient engineering. It remains the largest and oldest non-supported concrete dome in the world, and nearly two thousand years after it was built, it is still standing at the heart of Rome’s historic centre.
The building is entered through a monumental portico supported by sixteen large Corinthian columns made of Egyptian granite. There are still niches visible in these columns which were used to support market stalls when the exterior colonnade was used as a covered bazaar. This grand entrance leads into one of the most extraordinary interior spaces in ancient architecture.
Inside, the design is based on a clear geometric principle: a sphere contained within a cylinder. The diameter of the dome is equal to the height from the floor to the oculus, creating a precise sense of proportion throughout the structure.
At the centre of the dome is the Pantheon’s most famous feature, the oculus, a circular opening almost nine metres wide that allows natural light into the building. Throughout the day, sunlight moves slowly across the interior walls and floor. When it rains, water falls through the opening and drains away through small holes built into the ancient Roman pavement. You can visit on a rainy day and not get wet if you stand close to the walls.
The dome itself is constructed from unreinforced concrete and it becomes progressively lighter toward the top. The recessed ceiling panels, known as coffers, reduce the weight of the dome while also creating the distinctive pattern across the interior.
The Pantheon’s survival is largely due to its conversion into a Christian church in 609 CE by Pope Boniface IV. This transformation helped preserve the building at a time when many other ancient Roman structures were dismantled.
One notable episode in its later history occurred in the seventeenth century when Pope Urban VIII ordered the bronze from the portico top to be removed. Much of the bronze was reused in St Peter’s Basilica, most famously in Bernini’s monumental baldachini, the large bronze canopy above the papal altar supported by four twisting columns, representing curling incense.
The Pantheon is also the final resting place for several important figures in Italian history. The most famous is Raphael, the Renaissance painter and architect. Also buried here are King Vittorio Emanuele II, the first king of unified Italy, his son King Umberto I, and Queen Margherita of Savoy.
For many years entry to the Pantheon was free, which added to the sense that it was simply part of everyday Roman life. More recently, however, an entrance fee of five euros has been introduced, and visitors are generally required to book tickets in advance.
Even after living in Rome and returning many times since, the Pantheon remains one of the places I always visit. Standing beneath the dome and watching the light move through the oculus is still one of the most memorable experiences the city offers, and it’s even more special on a rainy day, never losing its impact, no matter how many times you return.
