London: Wealthy home owners who have added new basement floors are leaving a trail of entombed diggers around London because they are cheaper to bury than lift to street level.
Property experts estimate there could be up to 1000 excavators buried under sand, gravel and concrete, worth around £5 million ($9 million) in total.
The trend of adding new subterranean floors to London houses has become a highly lucrative business as space becomes harder to come by in the British capital. But although it is reasonably easy to get a digger into the rear garden of a home, it can become almost impossible to get it out after it has become nestled at the bottom of a building site.
In the past, developers would have used a large crane to scoop up the digger, but this is a costly and time-consuming process.
Now, in what is considered standard operating practice, they cover the digger with "hardcore", a mixture of sand and gravel, with a layer of concrete poured over the top.
Developers told the New Statesman magazine that in some of the newest extensions of London's most expensive homes, basement conversion specialists have encountered difficulties as they try to tuck "sub-basements" beneath the existing floors.
They say they are increasingly coming across abandoned diggers from the last round of improvements.