Swords are raised and fangs are flashed as the bloody, gruesome battle between man and beast begins. Nearly 2,000 years later, the Colosseum remains an iconic structure and symbol of Rome.

Some scholars suspect the secret may be hidden in the Colosseum's basement. The hypogeum, the Greek word for "underground," is a maze of corridors and collapsed walls.

Standing 48 meters high, 156 meters wide, and 189 meters long, the Colosseum featured a complex system of arches, vaults, and an underground network called the Hypogeum.

In the late 1990s, Heinz-Jürgen Beste of the German Archaeological Institute in Rome was studying the hypogeum when he started finding patterns, holes, notches and grooves in the walls.