Rome Mayor Roberto Gualtieri on Tuesday opened two new stations on the C line of the city's metro system, the Colosseo and Porta Metroni 'archeostations', so named because an array of the archaeological riches uncovered during their construction are on display in them.

Gualtieri said the new stations were "full-blown tourist and cultural attractions" in their own right.

"The challenge was to combine extraordinary archaeological heritage with engineering works," he said.

"Thanks to major projects like this, we are also rediscovering layers of the past that we would never have known about".

A museum at the Porta Metronia stop featuring the remains of a second century AD barracks, however, will not be ready to receive visitors for several months yet.