Sinkhole appeared outside HMP The Mount in Bovingdon , Hertfordshire . it was filled in with concrete and probably only fot it to re - open sometime later . It is just upstream from abbey road and appears to be 15 ft deep and 6 ft wide .
Sinkhole appeared outside HMP The Mount in Bovingdon , Hertfordshire . Hole was filled in with concrete and soil only fot it to re-appear days later . It is just yards from prison walls and believed to be 15ft deep and 6ft wide .