There was a building spree in England more than 5,500 years ago, when many of the most spectacular monuments in the landscape, were created.
Until recently it was thought that the hilltops enclosed by rings of ditches were worked on by generations of people, but experts from English Heritage worked with Cardiff University searching through hundreds of thousands of scraps of dating evidence, establishing that there was a concentrated building effort in the 50 years around 3700BC.
Read more at Cardiff University