In 110 AD, Emperor Trajan's architect Apollodorus of Damascus designed a semicircular, multi-level complex of 150 shops, offices, and administrative spaces carved into the Quirinal Hill. It was the world's first known multi-story commercial center — the ancestor of every shopping mall, every market hall, every covered arcade on Earth. Six levels of vaulted concrete rooms, connected by staircases and corridors, with a central hall (the Aula) whose engineering anticipates medieval cathedral construction by a thousand years. While millions of tourists photograph the Imperial Forums from behind the fence, the Mercati di Traiano — which you can actually ENTER and walk through — get a fraction of the visitors. This is one of Rome's most underrated sites. Rome guide → · Hidden Rome →
Plan my Rome trip →The Great Hall (Aula): A vaulted space with six cross-vaults that spans the full width of the complex. This was likely used for official distributions of grain and oil to Roman citizens. The acoustics are remarkable — stand in the center and whisper. Via Biberatica: An original Roman street running through the market complex, with shop doorways opening on both sides. The name probably comes from "biber" (drink) — these may have been ancient wine bars. You can walk the same cobblestones Roman shoppers walked. The semi-circular front: 150 tabernae (shops) arranged in a hemicycle that follows the curve of Trajan's Forum below. Each shop is a vaulted room with a doorway and a window — the architecture is standardized, modular, almost industrial.
Museum of the Imperial Forums (Museo dei Fori Imperiali): Inside the Mercati, the museum displays finds from ALL the Imperial Forums — fragments of colossal statues, architectural decorations, inscriptions. The multimedia reconstructions showing what the forums looked like at their peak are outstanding. The roof terrace gives the best aerial view of Trajan's Column, the Forum of Trajan, and the Forum of Augustus from above. This view alone is worth the ticket.
Address: Via IV Novembre 94 (entrance on the street level — most tourists walk past it without noticing). Tickets: €16 (Roma Pass valid). Hours: 9:30am-7:30pm, closed Mondays. Duration: 1-1.5 hours. Audio guide: €6, worth it — the architecture makes more sense with context. Accessibility: partially accessible (lower levels yes, upper levels involve stairs). Crowds: rarely crowded — even in peak season you'll share the space with 20-30 people. Compare that to the Colosseum's 25,000 daily visitors. Best time: late afternoon when the light hits the facade. Combine with: Colosseum (5min walk), Roman Forum (below you), Piazza Venezia (2min), Capitoline Museums (10min).