Europe's biggest construction project is currently underway in London: a new 73-mile long rail link passing underneath the British capital.
Crossrail – as it's called – will bring the city's transport system into the 21st century, increasing its rail capacity by 10 percent and carrying over 200 million passengers every year. But tunneling deep under a historic city like London means burrowing into the past.
"Crossrail is actually the largest archaeological dig that this country has seen in many,many years," observes the project's director Andy Mitchell.
Working alongside Crossrail's tunnel engineers, the company's small, in-house team of archaeologists has – so far – carried out dozens of excavations. Ten thousand items have been discovered from the Stone Age to the Roman period and through to the Victorian Era. The latest find – skeletons of victims of the plague or Black Death that swept through Europe in the 14th century – is causing real excitement in academic circles:
"It's fascinating stuff for us, giving us an insight into what the population was like in those years," says Don Walker of the Museum of London. "The find could shed further light on the biggest catastrophe to hit this city, causing huge social change. The Black Death wiped out perhaps half the population. Everything changed. Labor became scarce. And that's why there are theories that the plague was responsible for ending feudalism."
Crossrail is in the business of building a rail link but like all companies carrying out major construction projects on historically important sites in Britain it is legally obliged to employ the services of professional archaeologists.
"Virtually all of the archaeology in Britain these days is actually done as a response to a commercial development , funded by the developers themselves," says the Museum's Nick Elsdon.
Crossrail is spending $9 million on sifting and preserving the artifacts and human remains that it has come across; that's out of a total construction budget of $25 billion. A small price to pay – it says –for delving into the city's extraordinary past.
"You know this is a historic project," says Crossrail's Andy Mitchell. "We're building the future's history. So I think we engineers have a natural empathy with archaeology , certainly in a town like London."