In a last ditch attempt to save Silbury from collapse, English Heritage undertook a ‘conservation’ project during 2007-2008 to stabilise the structure and remove the detritus of previous tunnelling. Sadly, not only has much of this detritus been left within the structure, but parts of the original monument (eg the sarsen stones pictured below)* seem not to have been returned to their original position within Silbury Hill. The present location of these stones, the meaning of which has attracted some speculation, remains unknown.

If that were not bad enough, English Heritage has introduced even more detritus into the monument in the form of thousands of plastic sacks filled with chalk rubble; these sacks were used to form partitions within the Atikinson/BBC tunnel so that the area behind each partition could be backfilled with a chalk slurry. One is force to ask why plastic sacking was used instead of blocks of chalk closer in composition the mound itself. We have no idea at present how long the life span of these sacks is nor whether they pose any long-term hazard to the monument as they break down.

Perhaps English Heritage would care to comment here (or on the Heritage Journal) on their decision to use plastic sacking rather than chalk blocks – a decision which seems so at odds with accepted conservation principles.

* Photos here - http://heritageaction.wordpres[...]2010/07/20/sacking-at-silbury/