Some of the hundreds of rare coins from the Iron Age which have been uncovered by archaeologists working on the HS2 route
Hundreds of rare Iron Age coins have been unearthed by archaeologists working on the HS2 route.
One excavator described the hoard of small coins, which were found in Hillingdon, west London, and date back to the first century BC, as a "once-in-a-lifetime find".
Under British law, the find could be recognised as "treasure" and acquired by a museum.
Bearing the side profile of the Greek god Apollo on one side, and a charging bull on the other, their design is based on coins struck in the French city of Marseille more than 2,000 years ago.
Excavation teams made the discovery after a storm disturbed the ground where they were buried.
Emma Tetlow, the historic environment lead for HS2's main contractors Skanska, Costain and Strabag, described the moment the team uncovered the small coins, known as "potins".
"We were coming to the end of our archaeological work on the site when we found a patch of soil that was a very different colour from what it would be expected to be," she said.