In ancient Rome, tens of thousands gathered at the Colosseum to watch enslaved men, condemned criminals and wild animals fight to the death. These grisly gladiator clashes required great feats of engineering: To make caged creatures and prize fighters emerge from underground as if by magic, the Romans devised a labyrinth of secret tunnels beneath the arena’s wooden, sand-covered floor.
These underground structures have remained exposed to the elements for more than a century, enabling the millions of tourists who visit the Colosseum each year to see them up close, according to Reuters. Now, the Italian government has pledged €10 million (around $12 million USD) toward the installation of a new, retractable floor that will restore the amphitheater to its gladiator-era glory.
“We want to give an idea of how it was, and we are seeking proposals from around the world,” Alfonsina Russo, director of the Colosseum, tells the Times’ Tom Kington.
Per BBC News, architectural designs for the ambitious renovation are due by February 1. Italian officials say they hope to complete the project by 2023.
During the four centuries that the Romans used the Colosseum, the hypogeum, or network of underground tunnels beneath the arena floor, resembled a “huge sailing ship,” wrote Tom Mueller for Smithsonian magazine in 2011.
The structure consisted of staging areas, ramps, pulleys, ropes and other mechanisms that allowed workers to create a seamless show aboveground. Engineers even devised an underground elevator of sorts that lifted lions, bears, leopards and other caged wild animals into the arena.
“The hypogeum allowed the organizers of the games to create surprises and build suspense,” Heinz-Jürgen Beste, a researcher at the German Archaeological Institute in Rome, told Smithsonian in 2011. “A hunter in the arena wouldn’t know where the next lion would appear, or whether two or three lions might emerge instead of just one.”
All told, the complex system of passages and lifts served a “single purpose” for the empire: “to delight spectators and ensure the success of shows that both celebrated and embodied the grandeur of Rome,” according to Smithsonian.
As Jonathan Hilburg reports for the Architect’s Newspaper, Italian authorities say the restored version of the floor will feature replicas of trapdoors, lifts and other mechanical elements used in Roman times.
“[The renovation] will be a major technological intervention that will offer visitors the opportunity to not only see the underground rooms ... but also appreciate the beauty of the Colosseum while standing in the center of the arena,” says Culture Minister Dario Franceschini in a statement quoted by BBC News.
He adds that the retractable area must be able to close quickly in order to protect the ancient tunnels from the elements.
After the collapse of the Roman Empire in the fifth century A.D., the Colosseum fell into disrepair, alternatively serving as a quarry, a fortress and a convent. Partially dismantled as a “handy source of building materials,” the amphitheater’s stones were later repurposed during construction of St. Peter’s Basilica and other Baroque churches, according to History Today’s Ann Natanson.
The hypogeum, meanwhile, was eventually filled with dirt and rubble. By the early 20th century, when archaeologists first started restoring and researching the space, the tunnels had become overgrown with plants.
Russo tells the Times that after the renovation, the Colosseum plans to host concerts and theater productions on the new floor.
“The arena will be used for high culture, meaning concerts or theater,” Russo adds, “but no gladiator shows.”