Avebury Henge in Wiltshire. The fascinating image of the henge below is a recreation looking from the south made by Alan Sorrell in 1958.....It also helps to convey just what an amazing sight it must have been when all the stones were in place.
I chose this photo for two reasons. The first is that I love this photo, I think it does a great job of capturing the innocence of childhood throughout the world. The second reason I chose this photo is because it illustrates the idea of depth of field. The focus is so intently on the child that there is no way to tell what is going on in the background.