Engineering Rome

Engineering Behind the Roman Colosseum

Engineering Behind the Roman ColosseumAuthor: Megan Anderson


The Colosseum, alternatively known as the Flavian Amphitheatre, is arguably Rome’s most well-known monument. The elliptical structure that spans 6 acres signifies the presence and importance of Roman Engineering, tying in multiple engineering concepts within its structure. After first seeing the Colosseum, I was immediately drawn to the repeated concrete arches lining the perimeter. Knowing that the Colosseum served as a main source of entertainment for the people in the heart of the city, I was intrigued by the scale of the project and the vulgar practices that were seen as entertainment and power. The building itself once defined religion and culture for the Roman community. The striking appearance of the building was breathtaking and I knew I wanted to study the Roman Empire’s largest amphitheater further. After viewing the exterior multiple times, taking an in-depth tour, then doing extensive literature and online research on the subject, I was able to learn and apply concepts about the history, construction, engineering, restoration, and modern-day use of the Roman Colosseum.


The start of the Colosseum dates back to 69 AD, when Emperor Vespasian built the amphitheater to restore the city of Rome to what it was prior to its Civil War (Cartwright, 2012). It was designed to be a place of entertainment for the people. A pre-existing, smaller amphitheater built by Statilius Taurus had been destroyed in the fire that took place in 64 AD (Pepe,n.d.). Vespasian’s decision to build the grand new amphitheater in the center of the city which Nero had previously claimed his property can be seen as a political gesture of switching this area back to community use and returning Nero’s property to the people, implying inclusiveness for the Romans. The Colosseum was to represent the wealth and power that flourished in the Roman Empire at the time (Pepe, n.d.).

The structure had to be planned wisely because its location was to be built where Nero’s manmade lake was held. 26-foot drains took out water from surrounding valleys while concrete doughnut-shaped foundations were placed under the outer walls and inner ellipse. Ground level was raised 23 feet out of the valley for the amphitheater to sit on. The amount of expertise that went into planning the project is one of the main contributors to why it is still standing today (Hopkins, n.d.).

Construction began in 72 AD, financed by relics taken from the Jewish Temple after the Great Jewish Revolt in 70 AD. The workforce consisted of 12,000 Jewish prisoners also taken from the Siege of Jerusalem. While the Jewish slaves were a source of unskilled labor, the Romans undertook more specialized jobs. Prisoners worked long, hard hours under harsh conditions, including transporting travertine building blocks from a quarry 20 miles away in Tivoli. The construction took eight years, a considerably fast duration for having little equipment and being built on top of Nero’s lake. After Vespasian died in 79 AD, his son, Titus, took over and held the 100-day long inaugural games at the new Flavian Amphitheater in 80 AD, sponsored by the Emperor, where animals and gladiators fought until death. Spectators came out each day and watched long hours of gladiatorial battles, among other shows. Inside the Colosseum, these battles were seen as extreme entertainment that symbolized supremacy of the Roman community.

The complete structure, measuring 620×513’ and a capacity of more than 50,000 spectators (, 2010), is shaped as an Amphitheatre, a shape created by the Romans by combining two semicircular theatres to make a continuous ellipse (Pepe, n.d.). The building aimed to provide various types of entertainment to serve the Roman community. Seats were arranged by social class – the Emperor had the best set in the house, while senators had the next best seats reserved for them. The architect, who is unknown, wanted to build with a ratio of 5:3, or 300×180 Roman feet. Symmetry showed that the width of the arena, width of the auditorium, and height of the external façade were all equal. The perimeter, 1,885 Roman feet, was important to design because 80 equal arches needed to line its entirety (Hopkins, n.d.). The Roman concepts of proportions and symmetry are found elsewhere throughout the building. Roman engineering concepts, such as arches, columns, and vaults, are very common in the design as well.
Below is a figure of the structure in plan view as it was built in 82 AD.

Figure 1. Plan View of Colosseum

View of the amphitheater that displays seating and layout.

The cavea made up the seating portion of the auditorium, structurally supported by vaults underneath. The first three rows, reserved for senators, were made of marble seats. The succeeding rows were made of travertine for normal spectators. Sections were divided vertically and seats were chosen by social class (Pepe, n.d.).

In its earlier days, the most common battles were venationes (hunts of wild animals) and munera (gladiatorial games). The games were first strongly associated with religion and magic, but this connection came to a close as time went on. The most popular game were chariot hunts were held in the circus. Other practices that took place include re-enactments of famous battles, dramas based on mythology, and executions of condemned criminals. The games were regulated by laws and were driven by interest of the public. The last recorded gladiatorial game in the Colosseum was in 438 AD, when Valentinian III abolished these practices (Nero, n.d.).

In the Medieval era, a small chapel was built and the arena was used as a cemetery. Later, spaces under the vaults were rented out as housing and workshops until the 12th century. After a major earthquake destroyed two-thirds of the building in 1349, the remaining third was taken over by a religious order until the 19th century, but otherwise the monument was neglected for a number of centuries.
In the Modern era, the façade has been reinforced and restored multiple times and has become one of the most popular tourist attractions in the center of Rome, hosting tours to 4 million tourists each year (Wikipedia, n.d.).

Originally, the amphitheater had the capability to transport water from the Aqua Claudia aqueduct, the city’s main water source, to flood the substructures and create navy battle scenes. In later years, when Titus’ brother Domitian took power, the hypogeum was excavated to hold the fighters before the shows started, thus ending naval battles. Once the hypogeum was built, the construction of the entire structure was considered finalized.

Many disasters have taken place over the years which have destroyed the structure, some worse than others. Though the amphitheater was abandoned for multiple centuries, and two-thirds of the structure was torn down, multiple restorations have taken place to keep the building standing and maintain its historical significance. Restorations are still in effect to this day. Refer to the “Building Restorations” section to learn more.

The Amphitheatre was, and is, located in the heart of Rome, in between the Esquiline, Palatine and Caelian Hills. The structure was built where Nero once claimed his land and held his artificial lake. Because the Colosseum is the tallest ruin in Rome at 48 meters tall, it is hard to miss when you are in the neighborhood. I passed by the structure many times throughout my stay in Rome.