I'm confused.....again.
The situations at Stonehenge and Silbury Hill are two entirely separate issues.
The wheels began to turn for a solution to the mess at Stonehenge years before the large collapse at Silbury Hill. There is no connection whatsoever - other than they are both parts of World Heritage Sites which are in dire need of serious attention.
Stopping work on one wont assist the other site in any way whatsoever.
We could be having a serious discussion here about the Stonehenge visitors' centre but people seem to prefer to talk about Silbury Hill on this thread - a totally un-related topic, in my opinion.
:o)
Baz