Pantheon

The Pantheon: What Happens When a Roman Emperor Gets Engineering Right

The Pantheon in Rome is a building that architects have been studying, arguing about, and copying for nearly two thousand years. Built around 125 CE under the Emperor Hadrian on the site of two earlier temples, it remains the best-preserved building from classical antiquity and arguably the most influential structure in western architectural history. Brunelleschi studied it before designing the Florence Cathedral dome. Michelangelo measured it. Jefferson copied it for the Rotunda at the University of Virginia. Its proportions are still taught in architecture schools.

This is not, in other words, just another Roman ruin. It is a building that is still working, still used, and still surprising visitors who expect to be underwhelmed after seeing so many photographs.

What to Look At

The exterior is approached through a porch of sixteen Corinthian granite columns, the largest monolithic columns surviving from antiquity. The bronze doors (12 tonnes, 4 metres high) are Roman originals. Cross the threshold and the interior immediately does the thing that photographs cannot capture: the dome.

The concrete dome spans 43.3 metres, and the interior height of the building (from floor to the apex of the oculus) equals exactly 43.3 metres. The building is a perfect sphere. The Romans achieved this through coffers that lighten the dome’s weight as it rises and through varying the concrete aggregate – pumice and volcanic material at the top, denser stone at the base. The oculus at the centre is nine metres in diameter and open to the sky. Rain falls through it onto the sloped and slightly channelled floor. The light that enters at midday creates a single shaft that moves across the interior as the sun passes; on the feast day of Pentecost, rose petals are dropped through the oculus from above.

The floor is original Roman paving (or very close to it), with coloured marble panels in geometric patterns. The niches around the wall originally held statues of the planetary gods. Now they contain Christian altars and two royal tombs: Raphael (died 1520; his remains are here by his own request) and the first two kings of unified Italy, Vittorio Emanuele II and Umberto I.

Admission and Crowds

The Pantheon began charging an admission fee of 5 EUR for the first time in 2023, having previously been free. This has reduced the most egregious queuing but the building is still very busy from mid-morning until early evening in summer. Arrive at opening (9am) for relatively manageable crowds and the best morning light through the oculus.

A timed-entry system operates; book online at coopculture.it or at the entrance. The interior has a dress code (no shorts above the knee, shoulders covered) and a noise policy (guides with groups are asked to keep voices down; this is largely ignored but is evidence of intent).

Around the Pantheon

The Piazza della Rotonda immediately outside is permanently set up for tourism: overpriced cafes, ice cream sellers, the Fontana del Pantheon (a 15th-century basin topped by an Egyptian obelisk). Avoid eating here; prices are elevated relative to everything two streets away.

Sant’Eustachio il Caffe on Piazza Sant’Eustachio, three minutes’ walk away, is the most serious coffee bar in a city that takes coffee seriously. The espresso is made with a proprietary roast and served pre-sweetened unless you specify otherwise; the caffe speciale is their signature and genuinely excellent.

Piazza Navona is ten minutes’ walk west and has Bernini’s Fountain of the Four Rivers (1651), three churches, and a substantial tourist market. It is impressive; have a look.

The Campo de’ Fiori is in a different direction, fifteen minutes south. The morning market (7am-2pm, closed Sunday) sells vegetables, fish, and flowers at reasonable prices and is an authentically non-tourist experience in a central location.

Accommodation Near the Pantheon

Hotels in the immediate Pantheon area are expensive and some trade aggressively on proximity. The Albergo del Senato directly on the piazza has Pantheon views from its terrace rooms, which is a legitimate draw at a price. More practical is to stay in the Monti or Trastevere neighbourhoods (excellent restaurants, reasonable prices) and take public transport or walk 20-25 minutes to the Pantheon.

A Small Historical Note

The famous inscription on the facade – “M. AGRIPPA L. F. COS TERTIUM FECIT” (Marcus Agrippa, son of Lucius, built this in his third consulship) – refers to the first Pantheon on this site, built in 27 BCE. Hadrian, who rebuilt the entire structure nearly 150 years later, kept Agrippa’s name on it rather than his own, a piece of modesty unusual in Roman emperors and one that confused later historians for centuries.