I was looking through some photos and found this:

http://viewfinder.english-heritage.org.uk/search/reference.asp?index=193&main_query=&theme=ARCHAEOLOGY&period=&county=&district=&place_name=&imageUID=17112&=&JS=True

When i heard "backfilled with chalk" i didn't expect them to leave the wrappers on....

Some lovely photos in that series though.