Architecture of the Colosseum
The Colosseum is 52 metres high.
The minor axis of 156 metres.
The major axis is 188 metres.
The arena has an area of 3357 square metres.
The characteristics of the Colosseum
The structure is articulated on the outside in four orders, corresponding on the inside to five sectors of seats constituting the cavea. The load-bearing structure is formed of travertine block pillars interspersed in the first order by masonry in tuff blocks, in the upper orders by radial brick partitions. The roofing vaults are made of yellow and orange tufa concrete, the former from the Flavian period, the latter from the Severian period.The floor of the first order was made of travertine slabs, except along the corridor next to the arena, which, as it was intended for the senators, was covered with marble. In the upper orders the floor was in opus spicatum, made of brick bricks arranged in a herringbone pattern. Travertine was still used in the cladding of staircases and landings and in the visible ducts. The brick and tuff vaults and walls were covered with white plaster; the base of the walls was red. All pathways for the emperor, the senatorial order and the highest religious authorities were clad in marble.
The structure of the Flavian amphitheatre
The amphitheatre rises on a low crepidine of travertine blocks forming two tiers. The first three tiers are formed by 80 arches set on pillars in opus quadratum, with projecting semi-columns surmounted by Doric capitals on the first tier, Ionic on the second, and Corinthian on the third. The fourth and last register consists of a solid wall in which pilasters of Corinthian order alternate with square windows. The travertine corbels on which the base of the wooden beams that supported the roof velarium rested are still visible; holes for the insertion of the beams, one for each of the corbels below, open in the projecting cornice.
Delving into the architecture of the Colosseum
The cavea was subdivided from the bottom into a first sector of seats (podium) comprising four large marble tiers on which the senators' movable seats rested; a second sector, the maenianum primum, consisted of eight marble steps; the maenianum secundum, the largest sector, was divided into imum and summum and was reserved for the equestrian order; the maenianum summum in ligneis was located in the highest part just below the velarium and had 11 wooden steps below a colonnade. Elliptical corridors called praecinctiones separated the various sectors of seats: the praecinctio that distinguished the lower from the upper maenianum formed a high elevation articulated in doors, vomitoria (corridors for the exit of the crowd) and niches.
How many people could the Colosseum in Rome hold?
It has been calculated that the amphitheatre could hold about 55,000 spectators, of whom 50,000 were seated and 5,000 standing in the highest part. Around the arena ran a gallery of which only the back wall with 24 niches is preserved, which communicated with the games floor through doors used by the service personnel. A small portion of the service gallery was rebuilt in the 19th century along the southern slope, to emphasise the presence of the imperial cryptoporticus, which at this point reached the stage for the emperor.
Admission to the amphitheatre was free of charge but regulated according to a precise hierarchical criterion: the best seats around the arena were reserved for the senators, while the worst, higher and more distant seats with reduced visibility, were reserved for the plebs and were located in the maenianum summum in ligneis.
The entrances were numbered: some numbers can still be seen on the top of the arches of the outer ring along the intact north side. On the tops of the inner arcades were painted other indications that allowed spectators to easily find their way to their assigned seats: the same indications were written on the personal card that each citizen had. Only the entrances at the ends of the major and minor axes were not numbered as they were reserved for the authorities and gladiators.
In the Colosseum, in addition to gladiatorial fights (munera) and hunting shows (venationes), executions of death sentences (noxii) took place, which for the Romans had a high educational value as a warning to adhere to socially correct behaviour. Public executions became more frequent in the Late Empire, when certain types of torture such as the gallows and crucifixion disappeared, while burning and beheading survived.
The Gladiators' Dungeon
The floor on which the spectacles took place, the arena, completely hid from the spectators' view the underground rooms where all the activities connected with the staging of the games took place. The arena was sprinkled with sand (hence the name "arena") useful both to avoid slipping and to absorb the copious blood from the killing of large animals. The underground passages of the Colosseum were open from 80 AD until 508 AD, when they were completely filled with earth. The walls visible today are the result of a series of structural changes, not always easy to understand, due to both restoration and scenographic changes. The basements housed the hoists (80 in number) used to allow communication with the arena floor and to quickly bring out men, animals, scenery and materials needed for the games. The difference in height between the floor of the dungeons and the first order was 6 metres. The elliptical space of the dungeons is divided into four symmetrical sectors delimited by two main corridors set along the main axes, which intersect at right angles. The tufa walls, on which the grooves for the insertion of beams and the vertically grooved guides for the hoists are visible, date back to the original construction phase of the Domitian period. During excavations between 1874 and 1875, many wooden elements pertaining to the lifting mechanisms were found, and even an entire wooden floor, found intact in the central corridor, still in place perhaps to insulate the floor from rising water.
Buildings serving the amphitheatre
The construction of the amphitheatre also involved the simultaneous construction of a series of service buildings, all dating back to Domitian (81-96 A.D.).): the four Ludi, or gyms for the training of gladiators and venatores (the Ludus Magnus at the beginning of Via Labicana is well preserved), the barracks for the sailors of the fleet from Cape Misenum (Castra Misenatium) in charge of manoeuvring the velarium, the Summum Choragium, or the storehouse for the sets, and the Armamentaria, the gladiators' weapons storehouse. There was also the Saniarium, first aid for the wounded that could be treated on the spot, and the Spoliarium, where the undressing of the bodies of slain gladiators and the recovery of armour took place.