Emerging from the basalt-paved lanes of the ancient Campus Martius into Piazza della Rotonda, the traveler stands before sixteen monolithic granite columns rising nearly twelve meters high to support the triangular pediment of the Pantheon. Across the frieze below the pediment, the bronze-lettered Latin inscription of Marcus Agrippa from the 1st century BCE still commands the square. Directly behind that Corinthian portico stands a massive brick-faced cylindrical drum more than six meters thick, enclosing a sacred interior that has endured nearly two millennia at the heart of the Eternal City.
Stepping across the threshold through seven-meter-tall ancient bronze doors, the sensation of weight gives way to the serene geometry of an unreinforced concrete hemisphere spanning 43.3 meters in diameter. Devoid of exterior windows, the rotunda is illuminated solely by the Oculus, an open circular aperture nearly nine meters across at the crown of the vault. A shaft of direct sunlight travels slowly across five concentric rings of recessed coffers and descends onto the original imperial floor of red porphyry, Egyptian granite, and yellow Numidian marble, where the Renaissance master Raphael rests beside the altars of the Virgin Mary and the Christian Martyrs.
IFrom Roman temple of all gods to the Basilica of St. Mary and the Martyrs
The name Pantheon derives from the Ancient Greek Pantheion (combining pan, meaning "all", and theos, meaning "god"), signifying a sanctuary dedicated to all divinities or a temple reflecting the divine cosmos. Writing in his Roman History in the early 3rd century CE, the Roman senator and historian Cassius Dio (c. 155 - 235 CE) noted that the building received this name either because statues of many deities stood in its niches alongside Mars and Venus (the ancestral patrons of the Julian-Augustan house), or, as Dio himself favored, because its vaulted dome resembled the overarching canopy of the heavens.
The decisive historical turning point that preserved the Pantheon as the only ancient Roman monument to survive completely intact from vault to marble floor occurred in the early 7th century. In 609 CE, the Byzantine Emperor Phocas formally granted the imperial building to Pope Boniface IV (Bonifacio IV). On May 13, 609, Pope Boniface IV consecrated the rotunda as a Christian basilica under the title Sancta Maria ad Martyres (Saint Mary and the Martyrs). According to the Liber Pontificalis (Book of the Popes), twenty-eight wagonloads of sacred bones of early Christian martyrs were translated from the subterranean catacombs outside the walls of Rome and entombed beneath the high altar. This dedication on May 13, 609 laid the liturgical foundation for the institution of the Solemnity of All Saints (Omnium Sanctorum) throughout the Western Church.
The enigma of Marcus Agrippa's inscription on the facade
For centuries, the monumental Latin inscription across the portico architrave, "M. AGRIPPA L. F. COS. TERTIVM FECIT" (Marcus Agrippa, Lucii filius, consul tertium, fecit, meaning "Marcus Agrippa, son of Lucius, consul for the third time, built this"), led scholars to assume that the circular domed building dated to 27 BCE. In the late 19th century, however, systematic archaeological examination of Roman brick stamps (bolli laterizi) throughout the rotunda walls and vault demonstrated conclusively that the entire circular structure was built anew in the early 2nd century CE, initiated late under Trajan and completed under Emperor Hadrian between circa 118 and 128 CE. As recorded in the Historia Augusta, Hadrian followed a strict policy of never inscribing his own name on monuments he erected or restored in Rome, choosing instead to reproduce the original dedicatory inscription of Marcus Agrippa on the new portico.
Because of its cylindrical drum and circular plan, medieval and Renaissance Romans popularly called the church Santa Maria Rotonda or simply La Rotonda, giving rise to the modern name of the square and fountain before its entrance, Piazza della Rotonda.
IITwo millennia of history from the Augustan age to the present
The architectural history of the Pantheon encompasses three Roman imperial phases followed by more than fourteen centuries of uninterrupted Christian worship. The original sanctuary was erected between 27 and 25 BCE by the statesman, general, and architectural patron Marcus Vipsanius Agrippa, son-in-law and close colleague of Emperor Augustus, as the centerpiece of his monumental building program in the Campus Martius. Agrippa's structure was severely damaged in the great fire of Rome in 80 CE and restored by Emperor Domitian, only to be struck by lightning and burned again in 110 CE during the reign of Trajan. Beginning either in the final years of Trajan around 114 CE (as indicated by brick-stamp studies by Lise Hetland and others) and carried to completion under Emperor Hadrian between 118 and circa 125 - 128 CE, the temple was radically rebuilt on its present grandiose rotunda plan, often attributed to the imperial architect Apollodorus of Damascus.
- 27 - 25 BCEMarcus Agrippa constructs the first PantheonDuring his third consulship following the Battle of Actium, Marcus Vipsanius Agrippa builds the first Pantheon in the Campus Martius under Emperor Augustus.
- 80 - 110 CETwo destructive fires under Titus and TrajanAgrippa's temple burns in the great conflagration of 80 CE, is restored by Emperor Domitian, and is struck by lightning and destroyed again in 110 CE under Trajan.
- c. 118 - 128 CEEmperor Hadrian completes the present domed rotundaEmperor Hadrian reconstructs the Pantheon from the foundations up as a monumental cylindrical rotunda crowned by a 43.3-meter concrete dome fronted by a sixteen-column granite portico.
- 202 CEImperial restoration by Septimius Severus and CaracallaEmperors Septimius Severus and Caracalla restore the building and carve a secondary two-line Latin inscription on the architrave directly beneath Agrippa's frieze.
- 05/13/609Consecration as a Christian basilica by Pope Boniface IVFollowing the gift of the monument by Byzantine Emperor Phocas, Pope Boniface IV translates martyrs' relics from the catacombs and consecrates the Basilica of St. Mary and the Martyrs, saving the structure from medieval spoliation.
- 1520Entombment of Raphael and foundation of the Virtuosi al PantheonThe Renaissance painter and architect Raffaello Sanzio (Raphael) dies on April 6, 1520, and is entombed at his request beneath the statue of the Madonna del Sasso in the Pantheon. In 1542, the Pontifical Academy of Fine Arts and Letters of the Virtuosi al Pantheon is established.
- 1878 - 1900 & 1980Royal tombs of Italy and UNESCO World Heritage inscriptionItaly's first two monarchs, King Vittorio Emanuele II (died 1878) and King Umberto I together with Queen Margherita (died 1900), are entombed in the principal side chapels. In 1980, the monument is inscribed on the UNESCO World Heritage List.
Standing beneath the vault of the Pantheon, the Renaissance master Michelangelo Buonarroti famously declared that the building possessed "an angelic and not a human design" (disegno angelico e non umano). Its structural geometry directly inspired Filippo Brunelleschi's dome in Florence, Donato Bramante and Michelangelo's dome for St. Peter's Basilica, and Andrea Palladio's classical treatises across Europe and the Americas.
IIIThe 43.3-meter sphere, graded Roman concrete, and the Oculus
The Pantheon unites three distinct architectural volumes: a rectangular classical portico (Pronaos), a transitional brick intermediate block (Avancorpo), and a vast circular drum (Rotonda) surmounted by a hemispherical dome. Measuring 34 meters wide by 15.6 meters deep, the portico is supported by 16 monolithic granite columns arranged in three ranks: eight gray granite columns across the front facade quarried at Mons Claudianus in Egypt's Eastern Desert, and eight red granite columns in two interior rows quarried at Aswan along the Nile. Each single-stone shaft stands 11.8 meters (40 Roman feet) tall, measures 1.48 meters in diameter, and weighs roughly 60 metric tons, having been barged down the Nile, shipped across the Mediterranean to Ostia, and towed up the Tiber River to Rome.
The 43.3-meter interior sphere and graded-aggregate concrete engineering
The interior of the rotunda is governed by a sublime geometric proportion: the internal diameter of the cylinder measures exactly 43.3 meters (150 Roman feet), which is identical to the vertical height from the marble pavement to the apex of the Oculus (43.3 meters). Because the lower cylindrical wall rises 21.65 meters to the springing line and the hemispherical dome rises another 21.65 meters above it, a complete sphere 43.3 meters in diameter fits precisely within the interior volume. Nearly 1,900 years after its completion, the Pantheon remains the largest unreinforced solid concrete dome (opus caementicium) in the world.
To prevent the 4,535-ton concrete vault from collapsing under its own weight and outward hoop tension, Hadrian's engineers combined four ingenious structural techniques. First, the supporting drum wall was built 6.2 meters thick and honeycombed with internal brick relieving arches and void chambers that channel loads onto eight massive piers between seven recessed ground-floor niches. Second, the shell of the dome tapers progressively in thickness from 5.9 meters at its base to just 1.2 meters around the upper Oculus ring, while external stepped rings add counterweight over the lower haunches. Third, the inner surface was molded with five concentric rings of 140 recessed trapezoidal coffers (lacunaria, 28 in each ring), reducing concrete mass while preserving a structural grid of ribs. Fourth, the builders graded the volcanic pozzolana concrete aggregate from heavy to light from bottom to top: dense travertine stone in the foundations, terracotta brick and tufa in the drum and lower vault, and featherweight volcanic pumice (pomice) in the uppermost ring around the Oculus.
The unglazed circular opening at the crown of the dome measures approximately 8.7 to 9 meters (30 Roman feet) across, lined with a compression ring of Roman bipedales bricks and original gilded bronze sheets. It serves simultaneously as the sole light source, a monumental solar calendar, and a structural relief opening at the point of greatest crown stress. Rainwater falling through the Oculus drains away through 22 small perforations drilled into the gently convex central marble floor.
Located in the principal southern apse opposite the entrance, the high altar remodeled by Alessandro Specchi in the early 18th century enshrines a revered 7th-century encaustic wood panel icon of the Mother of God and Child donated at the time of Pope Boniface IV's consecration.
Placed beneath the third niche on the left side under the marble statue of the Madonna del Sasso sculpted by his pupil Lorenzetto. The Roman sarcophagus bears Cardinal Pietro Bembo's celebrated Latin epitaph: "Ille hic est Raffael, timuit quo sospite vinci, rerum magna parens et moriente mori" (Here lies Raphael, by whom while he lived Great Mother Nature feared to be outdone, and when he died feared that she too would die).
Among the largest surviving ancient bronze doors from the Roman Empire, each leaf measures 2.27 meters wide by 7.53 meters high and pivots on sockets in the threshold and lintel beneath an open bronze transom grille.
The floor preserves its Hadrianic geometric layout of alternating circles and squares (echoing the sphere-within-a-cube geometry of the rotunda), paved with precious stones from across the Empire including red Egyptian porphyry, gray granite, yellow Numidian marble (giallo antico), and purple-veined Phrygian marble (pavonazzetto).
Alongside Raphael rest the painter Annibale Carracci, the architect Baldassare Peruzzi, and the composer Arcangelo Corelli, as well as the monumental royal tombs of King Vittorio Emanuele II, King Umberto I, and Queen Margherita of Savoy.
Every year on April 21, the traditional anniversary of the founding of Rome by Romulus in 753 BCE (Natale di Roma), at solar noon the circular beam of sunlight entering through the Oculus aligns directly with the arched bronze entrance portal of the Pantheon. Archaeoastronomers have demonstrated that Hadrian's architects calibrated the diameter and height of the Oculus so that when the Emperor crossed the threshold at midday on Rome's birthday, he walked directly inside a spotlight of solar illumination descending from the zenith.
IVThe lie of the land and sacred orientation
Ancient Roman temple planning and Catholic church architecture do not utilize East Asian geomancy, instead, the Pantheon was oriented according to the sacred cardinal grid of the Campus Martius and Roman augural sky-division (templum), and was subsequently consecrated by the Catholic Church with the high altar placed in the southern apse opposite the entrance. The following analysis offers a comparative reading through the classical landform principles of our library to examine the remarkable siting of the Pantheon within the topography of Rome.
The Pantheon stands at 41.8986 degrees north latitude and 12.4768 degrees east longitude at the heart of the level alluvial plain of the ancient Campus Martius (Field of Mars), cradled within the sweeping westward bend of the Tiber River (Fiume Tevere) to the north and west and encircled by the Seven Hills of Rome to the east and south. Across the macro-landform of the Eternal City, the Tiber descends southward from the Apennines and curves around the Campus Martius in a protective C-shaped loop resembling a jade belt embracing the node (ngọc đái hoàn bão). To the south and southeast rise Rome's two most sacred historic heights, the Capitoline Hill (Campidoglio) and the Palatine Hill (Palatino), serving as a solid rear backing (Rear Backing Mountain (Hou Zhen)), to the east stand the ridges of the Quirinal and Pincian Hills as flanking guardians, while across the Tiber to the west rise the Janiculum (Gianicolo) and Vatican Hills completing the protective ring.
A striking feature of the Pantheon's orientation is that it sits in the south and faces due north (unlike most Greco-Roman temples that faced east or south). Its sixteen-column portico opens directly toward true north (0 degrees north), looking out across Piazza della Rotonda (which in antiquity was a long colonnaded forecourt) along a direct meridian axis aligned with the circular Mausoleum of Augustus to the north. Internally, the pairing of the rectilinear portico with the cylindrical drum and 43.3-meter hemispherical dome embodies the classical geometric harmony corresponding to the cosmological principle of "round Heaven and square Earth" (Thiên viên Địa phương). At the exact zenith of the vault, the open 8.7-meter Oculus functions as a celestial sky-well (thiên tỉnh) drawing sunlight, moonlight, fresh air, and seasonal rain directly into the center of the sanctuary, sustaining the vitality of the monument for nearly twenty centuries.
VLiturgical solemnities and the Pentecost rose-petal rain at the Pantheon
Alongside its status as an architectural landmark of antiquity, the Pantheon remains an active minor basilica of the Diocese of Rome (Basilica Collegiata di Santa Maria ad Martyres), celebrating weekly Masses and centuries-old liturgical traditions.
| Date (Calendar) | Liturgical feast or observance | Traditional ceremonies and spiritual significance |
|---|---|---|
| Pentecost Sunday, 50 days after Easter | Solemnity of Pentecost and Shower of Red Rose Petals (Pioggia di petali di rose) | Following the 10:30 AM Solemn Mass on Pentecost Sunday, Roman firefighters stationed atop the exterior dome release millions of crimson rose petals down through the open Oculus from a height of 43.3 meters, symbolizing the tongues of fire of the Holy Spirit descending upon the Virgin Mary and the Apostles as well as the blood of the Christian martyrs. |
| April 21 (Gregorian calendar) | Anniversary of the Founding of Rome (Natale di Roma) | At solar noon on April 21, the circular beam of sunlight passing through the Oculus illuminates the main entrance portal in exact alignment with the Hadrianic astronomical design. |
| May 13 (Gregorian calendar) | Anniversary of the Dedication of Santa Maria ad Martyres | Commemorates May 13, 609 CE, when Pope Boniface IV consecrated the Pantheon as a Christian basilica dedicated to the Blessed Virgin Mary and all the Martyrs. |
| November 1 (Gregorian calendar) | Solemnity of All Saints (Solennità di Tutti i Santi) | Principal patronal solemnity of the basilica, celebrating the universal feast that originated directly from the 7th-century dedication of the Pantheon to Mary and the Martyrs. |
| April 6 (Gregorian calendar) | Commemoration of the Death of Raphael (1520) | The Pontifical Academy of Fine Arts and Letters of the Virtuosi al Pantheon celebrates a memorial liturgy and places red roses at the marble sarcophagus of Raffaello Sanzio. |
VILocation And How To Get There
- Address
- Piazza della Rotonda, 00186 Roma (RM), Lazio, Italia
- Getting there
- The Pantheon is located in Piazza della Rotonda in the historic center of Rome, just 300 meters east of Piazza Navona and 600 meters west of the Trevi Fountain. From Roma Termini central railway station, take bus Line 40 or Line 64 to the Largo di Torre Argentina stop and walk approximately 400 meters north along Via di Torre Argentina directly to Piazza della Rotonda.
- Coordinates
- 41.8986, 12.4768
Because the Pantheon is an active Catholic basilica of the Diocese of Rome (Santa Maria ad Martyres), please wear modest attire covering shoulders and knees, remove hats upon entering, and maintain respectful silence inside the rotunda. During Saturday vigil Masses, Sunday morning Masses, and Holy Days of Obligation, sightseeing visits are suspended so that the basilica is reserved exclusively for worshippers attending Mass. On rainy days, the central circular section of the marble floor directly beneath the open Oculus becomes wet and is cordoned off for safety.
Nearby places in the library
VIIContribute To This Page
Contribute photos, information or video for Pantheon, Rome
Contribute photos, historical notes, or videos for Pantheon, RomeEveryone is welcome to enrich this page: a photo you took, a detail the page misses, a short video. Every contribution is read and answered.
Master Ưng Khiêm invites the community to enrich this page. On-site photographs, historical details not yet mentioned, or short video clips: every contribution is personally reviewed and answered.
No community contribution yet. You could be the first. No community contributions yet. Be the first to contribute.
?Quick Questions
Who actually built the circular domed Pantheon that stands in Rome today?
Although the facade frieze still bears the Latin inscription of Marcus Agrippa (who built the original sanctuary between 27 and 25 BCE), that earlier structure burned in 80 CE and 110 CE. Roman brick stamps prove that the entire present circular rotunda and concrete dome were constructed under Emperor Hadrian between circa 118 and 128 CE, while preserving Agrippa's original inscription.
Why does the dome of the Pantheon have an open circular hole at the very top?
The circular opening at the apex of the dome is called the Oculus (Latin for eye) and measures nearly 9 meters across. Left completely open to the sky, the Oculus serves as the sole source of natural light for the interior, acts as a giant solar sundial, and eliminates heavy masonry at the crown where structural bending stress would be greatest.
What happens when rain falls through the open Oculus of the Pantheon?
When it rains in Rome, water falls directly through the open Oculus onto the center of the rotunda floor. Ancient Roman engineers designed the polychrome marble pavement with a gentle convex crown rising about 30 centimeters in the middle and drilled 22 small drainage holes that channel rainwater into subterranean Roman conduits.
Why is the Pantheon the best-preserved building from ancient Rome?
Whereas many ancient Roman temples were quarried for stone and bronze during the Middle Ages, the Pantheon survived intact because Byzantine Emperor Phocas gifted the monument to Pope Boniface IV in 609 CE. Consecrated on May 13, 609 as the Basilica of St. Mary and the Martyrs, it has been continuously maintained as a church for over 1,400 years.
Which famous historical figures are buried inside the Pantheon in Rome?
The Pantheon holds the tomb of the Renaissance painter and architect Raphael (Raffaello Sanzio, died 1520), as well as the tombs of painter Annibale Carracci, architect Baldassare Peruzzi, composer Arcangelo Corelli, and the first two monarchs of unified Italy, King Vittorio Emanuele II and King Umberto I with Queen Margherita.