There are international conventions that state that archaeology of all time periods is equally worthy of preservation. There are snippets on the web and elsewhere to suggest there are those that regard 18th and 19th century excavation tunnels as important parts of the archaeological record that must be studied and preserved.
My theory as to the cause of the international scandal that Silbury is that there are voices in EH who have succeeded in twisting the programme to take account of the tunnels.
Hard to believe that anyone could be so learned as to prejudice neolithic archaeology for the sake of the tunnels, but what other explanation can there be?
