Just a summary article of recent aerial discoveries
http://www.bbc.co.uk/news/uk-england-36912891
Good to see a more or less methodical approach being used here.
Apparently many of these things were noticed by RAF pilots in the 1920s and '30s, but there was nobody they could really tell, so that information fell by the wayside. Fortunately much of it is being retrieved today.
also there is a growing discipline of archaeology by satellite (google maps/earth or similar) imagery too. Fascinating stuff