Archaeologists excavating the listed Syon Park site made the discovery of more than 11,000 Roman items just half a metre below the ground.
They were digging on the land ahead of the construction of a new hotel on the outskirts of the historical Syon Park Estate, near Brentford.
Part of one of Roman Britain’s most important roads was also found.
About 11,500 fragments of pottery, 100 coins and jewellery were uncovered by the experts from the Museum of London Archaeology.
Jo Lyon, a senior archaeologist at the museum, said: “We were extremely fortunate to discover such a comprehensive repertoire of Roman finds and features so close to the surface.
“They tell us a great deal about how the people of this village lived, worked and died.