London’s archaeological dig.PHOTOGRAPH BY GETTY IMAGES

It’s one of Europe’s oldest capitals but London’s time-is-money ethic means chances to pause and poke beneath its surface are few. But, as America’s National Geographic magazine reveals in an in depth look under the city, the current building boom is giving archaeologists the chance to uncover treasures left by those who lived in the capital for millennia.

It’s an impressive haul. Under an office block in the City came a first-century fresco from an early Roman building. At a colossal 10x6ft, and painted with the finest pigments, including pricey cinnabar, it’s one of the biggest ever found in London — the City was ever a place of conspicuous wealth.

“The modern city sits atop a rich archaeological layer cake that’s as much as 30ft high,” said Roff Smith, reporting on the story in the February issue of America’s National Geographic magazine. And these layers tell stories that change the very foundations of the capital’s history. For example, recently uncovered at the new home of financial news agency, Bloomberg: one of the most important early Roman sites ever found in London — entire streets complete with timber-framed shops, homes, and yards, dating from the early 60s AD.

Sadie Watson from Museum of London Archaeology, who supervised the site, dubbed the discovery the “Pompeii of the north” with “the richest haul of small finds ever to come out of a single excavation in the city.” All near-perfectly preserved, thanks to what she called “good old English damp.”

But the biggest haul has come from the on-going Crossrail works. This 26-mile east-west commuter rail link that has turned much of the capital into a building site since 2009 is finally bearing fruit — as an invaluable archaeological catalogue of its past. Outside Liverpool Street station, for one, the new track ploughed through Bedlam, London’s first municipal cemetery unearthing 3,300 skeletons, many of whom were plague victims. Scientists are hoping to use these remains to learn about the evolution of the bacterium that once looked set to stop London in its tracks. But, as time and Crossrail works tell, it will take more than that. Read more at: ngm.nationalgeographic.com

Hotel historyAt a new Motel One site in London’s Aldgate, archaeologists uncovered one of the best-preserved sculptures from Roman Britain: a 1,900-year-old stone serpent held in the clutches of an eagle, thought to have adorned the mausoleum of an official.

This and many of the finds detailed in this story have or will be on show at temporary exhibitions held at the Museum of London and the London Transport Museum. museumoflondon.org.uk  ltmuseum.co.uk