article_snippet: A massive sinkhole has opened up just yards from the fence of a prison - but officials insist there is no chance of any inmates escaping.
article_snippet: Hole first appeared just outside the walls of HMP The Mount in Bovingdon, Hertforshire in January.
article_snippet: Staff at the 770-capacity prison filled A massive sinkhole with soil and concrete - but it re-emerged and is now believed to be about 6ft wide and 15ft deep.
article_snippet: A massive sinkhole has opened up close to the fence of HMP The Mount Prison - but officials insist there is no chance of any inmates escaping .
article_snippet: ft sinkhole has emerged yards from the walls of HMP The Mount Prison in Bovingdon, Hertfordshire .
article_snippet: the hole comes after a similar crater opened up in nearby Hemel Hempstead, Hertforshire, last February.
article_snippet: It is believed to have been caused by former chalk mines beneath the surface of the ground being exacerbated by the previous winter's heavy rain.
highlights_snippet: Sinkhole appeared outside HMP The Mount in Bovingdon, Hertfordshire .
  
highlights_snippet: Hole was filled in with concrete and soil