British archaeologists have discovered the ruins of an arena built early in the third century BC outside Ostia, the ancient imperial port 25 kilometres (16 miles) from Rome, the team leader said Friday.

The ruins were uncovered in three years of digging by the British team from Southampton and Cambridge Universities in cooperation with the British School at Rome, an archaeological academy.

Italian archaeologist Rodolfo Lanciani determined the approximate location of the site in 1868, but more systematic research finally led to its discovery 140 years later.