10 Secret Rooms Hidden In Famous Landmarks

Rome’s Colosseum attracts more than four million visitors each year, but not all of them realise there's more to the former gladiator venue than meets the eye.

Below street level lies a network of underground tunnels that were once used to house animals, such as lions and bears, before they were lifted into the arena via pulley.

This subterranean maze was hailed as a great archaeological discovery when it was first uncovered, and it was opened up to the public during the last decade, though access is limited to those on guided tours of a maximum of 25 people at a time.

Some archaeologists were outraged when they heard scores of tourists would be traipsing through the tunnels, potentially putting their structure at risk. To quote Russell Crowe in Gladiator, they were not entertained.