Happens more often than you'd think.I once watched an episode of Time Team where they went to the USA to where the Mayflower landed. The septics were horrified when they suggested bringing in a JCB to dig a trench. They had so little history to dig up they sieved the whole lot. Here in the UK you can't dig more than a few feet without finding a neolithic stove or some roman plumbing.
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Smallbrainfield,
Tue 5 Feb 2013, 15:03,
archived)