Must see

The lake under the Colosseum

The Colosseum, a wonder of the modern world, tells myths and stories of the city. It is certainly the most representative symbol of imperial Rome. Few people know, however, that underneath there are enchanting small lakes with crystal-clear water. Here, in fact, a labyrinth of underground lakes has been found that run for more than two kilometres. This is a system of Roman quarries, excavated from the 4th century B.C. onwards, which develops in a sequence of halls where the vaults vary from eight metres to passages of just one and a half metres. The origin of these quarries is probably due to an aquifer that has also been fed over the centuries by water infiltration.

Although there are electrified cables within the complex route, the tunnels are thought to have been used as air-raid shelters during the Second World War, the tunnels were only discovered in the 1980s, and a complete mapping was obtained between 2004 and 2006.