Beyond the entrance of Rome's newest metro station under the Colosseum, there are display cases filled with hundreds of ancient artefacts found during a decade-long construction project.

Spread out over four levels to a depth of 32 metres in the heart of Rome, the "Colosseo-Fori Imperiali" station on the city's C-line unveiled on Tuesday is a feat of modern engineering.

For the price of a 1.5-euro ticket, travellers can access the station's underground museum holding 350 objects -- from ceramic jugs and lamps to bronze statuettes and a wooden sword.

A little further, the remains of a bathhouse of the home of a wealthy Roman can be seen.

Ancient Rome was built in layers. Temples and forums were built on older foundations before themselves being covered over, creating a fascinating terrain for archaeologists.

At ground level, a triangular opening even offers an unusual viewpoint on the Colosseum.

"The most important thing that we have managed to do is to show an insight... into daily life," Elisa Cella, an archaeologist at the Colosseum archaeological park, said at the presentation.

Rome mayor Roberto Gualtieri called the station opening "an extraordinary and historic event".

He also defended the costly and lengthy works, which have caused widespread disruption for residents and tourists in the area for years.