The old map resource at http://maps.nls.uk/os/6inch-england-and-wales/ is a fantastic way to waste hours.
The ability to overlay old maps with modern aerial views is great.
As an example here is a shot of the area to the east of the New Visitor Centre at Stonehenge.
Apart from hoping they properly capped the well that was under the well house and is now underneath the gift shop I was intrigued by the mysterious "post" near Fargo Plantation.
Many hours of thought and it struck me that as the field is known as "The Gallops" it is probably just a finishing post or turn marker for training race horses. The field is owned by the Druids Lodge estate.
Druid's Lodge was famous for training racehorses and infamous for the Druid's Lodge Confederacy and the betting coup at the 1913 Derby.
Their secretly trained horse Aboyeur won, after a Stewards Inquiry, at 100-1, and they had been backing it all over the country in small amounts for months so as not to frightened the odds makers.
£14 million at todays money is rumoured to be their winnings.
More at http://www.lady.co.uk/people/features/2317-scandal-su-ffragettes-the-biggest-ever-betting-coup