The picture below is a trigger picture for an Aurasma augmented reality aura, showing how the ditch at Avebury has changed over 4,500 years. This picture is of the north east quadrant of the ditch by what is now the road to Wroughton. I have taken an image of the same stretch of ditch at virtual Avebury and made the pictures to the same scale and register.

To see the augmented image, go to the App store on your Apple or Android tablet or phone and download the Aurasma app.    Register with a username, password and email address, and then press on ‘discover auras’ and search for lizfal. Press on ‘follow’ and then press the small purple square at the bottom of the page. Your camera viewfinder will open. Find the image in your viewfinder and hold still for a few seconds – you should see the augmented image appear! You have to have a wireless connection or 3G active to be able to see the augmented image.