Architecture Around the World

Colosseum - Interior
Rome, Italy
Companion Page: Colosseum Exterior Photos

On each of the three levels with arches there were eighty passageways. Those on the first floor were numbered.

The arena of the amphitheater is 86 yards long and 50 yards wide. Around the arena there was a net to protect the spectators.

The surface of the arena, which consisted of wooden boards, was covered with sand.


Click on photos for larger view - and more information

On each of the three levels with arches there were eighty passageways

The subterranean areas beneath the arena

The enormous oval seating area


Brick facing over concrete

In contrast with Greek practice, the Romans employed concrete

The Cavea, which held the spectators, consisted of five tiers.

50,000 spectators

At the long ends of the arena there were two entrances: the southeastern one was the "Libitinarian" gate (from Libitina, goddess of funerals), through which were carried the dead gladiators and the wild beasts which had been killed; the other was the entrance gate for the processions of gladiators who paraded before the Emperor and the spectators before the beginning of the combats. "Ave, Caesar, Marituri te salutant! " (Caesar, those about to die salute you!)

The subterranean areas beneath the arena served to contain everything that was necessary for the spectacles There were cages to hold the wild beasts destined for the show and mechanical elevators by means of which the animals were made to appear on the surface of the arena.

Also worth noting is the existence of no less than five cryptoportici (covered galleries or corridors), of which one was decorated with stuccoes, mosaics and paintings on the wall. This structure seems to have been added by the Emperor Commodus, who used it to pass directly into the amphitheater

The Cavea, which held the spectators, consisted of five tiers:

It is calculated that the amphitheater could hold 50,000 spectators. The Coliseum was mainly used for gladiatorial flights and wild beast hunts; when these were held a strong net made of gilded metal was put up to protect the audience.

To shield the spectators from the sun a "velarium" was used, a movable cover consisting of a series of awnings stretched over cables, which were manipulated by sailors of the Capo Misenus fleet and specially stationed in Rome.

The Coliseum, like the much earlier amphitheater at Pompeii, could not have been built without concrete technology. The enormous oval seating area is sustained by a complex system of radial and concentric corridors covered by concrete barrel vaults. This concrete "skeleton" reveals itself today to anyone who enters the amphitheater; in the centuries following the fall of Rome the Coliseum served as a convenient for ready-made building materials, and almost all its marble seats were hauled away, exposing the network of vaults below.

Roman Arches

Philosopher Alfred North Whitehead wrote, "The Roman Empire existed by virtue of the grandest application of technology that the world had hitherto seen." This technology included engineering innovations like the arch, vault, and dome. For the first time, Roman builders spanned huge volumes of interior space, shaping an architecture of enclosed voids, not supporting mass. With the invention of concrete, they built increasingly daring forms, from baths to basilicas, on a vast scale.

The essential ingredient of Roman building was the arch. Although Romans were smitten by "superior" Greek style and plastered conspicuous columns on facades, they abandoned the column as an actual structural support.

The arch and its progeny - the vault and the dome - revolutionized architecture. A stone lintel atop two columns rarely spans a distance as wide as 15 feet, but an arch can span 150 feet. Additionally, when its keystone is locked into place, the arch supports itself as well as immense loads on top. Combined with concrete, which could be cast in molds of any shape and scale, the arch allowed Romans to enclose enormous spaces and fully exploit the potential of these new forms and materials.

When an arch is extended in a straight line, or multiplied in depth, it becomes a barrel (or tunnel) vault. Such vaults provide a curved ceiling over two parallel walls and may be combined to form arcades (as in the Coliseum) supporting multiple tiers of superstructure. When two barrel vaults intersect at a right angle, the juncture forms a groin or cross-vault, which provides lunette windows for lighting at either end. An arch, rotated 360 degrees, creates a dome. By the first century B.C.E., the arch and vault were pervasive in Roman buildings.

Ancient concrete was not liquid but a viscous mixture of sand, lime, water, and aggregate. It was laid down in layers inside wooden or brick form work and solidified into a dense artificial stone that was light, strong, fireproof, and monolithic. Roman concrete walls and shells were always lined on both the exterior and interior with brick or a veneer of decorative stucco, fresco, mosaic, or marble. Purely ornamental columns, like olives dressing up a plain salad, adorned arches for a touch of Greek zest. The columns were generally engaged, or partially embedded in walls. When flattened and squared off, they are known as pilasters.


Photos and their arrangement 2002 Chuck LaChiusa
| ...Home Page ...| ..Buffalo Architecture Index...| ..Buffalo History Index... .|....E-Mail ...| .

web site consulting by ingenious, inc.