The museum occupies the ruins of boutiques, food stores, and workshops that formed Emperor Trajan’s Market, now home to 172 marble fragments from the Imperial Forums; here are also original remnants from the Forum of Augustus and Forum of Nerva.

Created in a.d. 100–110, but having fallen into total ruin, this once-bustling “shopping mall” was built over in the Middle Ages and then extensively excavated under Mussolini. The Imperial Forums, many of which are still being excavated, are hard for ordinary visitors to understand, so the museum uses replicas to help visitors orientate themselves, plus galleries housing models and reconstructions of the various forums and temples. It also houses a giant head of Constantine, found in 2005 in an old sewer. Tickets are 14€, so perhaps intended for those with a deeper historical interest in Ancient Rome.