The iconic stone monument in England - and it's surrounding areas served as a burial ground from its earliest beginnings. But besides that, not much is known about how or why the henge was constructed. Was it a religious place? A way to keep track of time? Or maybe even a giant open-air disco? And what about all the other henges? Are they related? The mysteries surrounding it - and the vast amount of interpretations possible - have made it one of the most well known - and parodied - heritage sites around the world.