This striking museum showcases the Mercati di Traiano (Trajan's Markets), the emperor Trajan's towering 2nd-century complex, while also providing a fascinating introduction to the Imperial Forums with multimedia displays, explanatory panels and a smattering of archaeological artefacts.
Sculptures, friezes and the occasional bust are set out in rooms opening onto what was once the Great Hall. But more than the exhibits, the real highlight here is the chance to explore the vast structure, which historians believe housed the forums' administrative offices.
Originally, scholars thought the three-storey hemicycle housed markets and shops – hence its name – but more recent theories dispute this, holding it was probably used to house offices staffed by the forums' administrators and managers.
Rising above the markets is the Torre delle Milizie, a 13th-century red-brick tower.