The stone coffin dates back approximately 1,500 years. Credit: National HighwaysShareConstruction workers expanding a section of road north of London needed to pause their project after uncovering an unexpected finda small Roman cemetery dating back roughly 1,500 years. Excavating just one of the coffins in their way was no small feat, either. According to the Englands National Highways department announcement on January 6th, the largely intact stone casket weighed as much as an adult male polar bear. For those unsure about that exact unit of measurement, that puts the coffin at around 1,650 lbs.While our main focus has been on building a road to improve journeys for road users, its been extremely satisfying to play a part in uncovering such an unusual archaeological find, said Chris Griffin, the National Highways east region program leader.The coffin weighs roughly 1,650 lbs. Credit: National Highways While a sovereign state today, a large portion of the UK once composed the Roman territory of Britannia. Julius Caesar initially invaded the island in 55 and 54 BCE during the Gallic Wars, but it wasnt until Claudius reign that a much larger campaign commenced. Rome officially annexed the province of Britannia in 43 CE before ruling over the region for roughly the next 400 years. This means that locals likely buried the large stone coffin towards the end of Roman occupation following almost a half-century of cultural exchange and improvements made to Britains agriculture, architecture, urban planning, and industry. One of the most notable Roman additions to the area was a vast network of roads connecting much of the territory. Despite their immense influence, however, only an estimated 800 Latin words were ultimately incorporated into Common Brittonic by the time of Romes withdrawal from the island. The vast majority of the proto-English language remained firmly intertwined with its Germanic origins. Get the Popular Science newsletter Breakthroughs, discoveries, and DIY tips sent every weekday. By signing up you agree to our Terms of Service and Privacy Policy.David Harrison, project manager for Headland Archeology overseeing the dig, called the coffin a fascinating discovery that is extremely unique to the region. Its careful excavation and recording, both in the field and the laboratory, allows us to continue to learn how our Roman ancestors lived and died, he added.The coffin is just one of a number of artifacts recovered along the stretch of A47 north of London near Cambridgeshire. According to Archeology News, a team of 50 archeologists and 20 civil engineers spent seven months excavating 17 different sites along the roadway. Many of these discoveries will be showcased in the new season of Digging for Britain. The first episodewhich includes the polar bear-sized casketwill premiere on BBC 2 on January 7th.