After visiting the Preseli Hills in Wales I became fascinated by the mystery of Stonehenge's rocks. Half of them come from these hills in Wales over 260 km away. You can see it when you are there, they look exactly like the rocks that make up parts of Stonehenge, but it baffles the mind as to how they got to the site at Stonehenge. I started to read more about this prehistoric mystery and talking to scientists and I learnt about how much we do and don't know about this monument so I wrote about it for BBC Travel. I am still amazed at Stonehenge and what it may represent, I think there is still a lot that we don't know about this place but scientists are working hard to understand what prehistoric man was up to all those years ago.