Stonehenge, in many peoples' minds, is the most mysterious place in the world. This set of stones laid out in concentric rings and horseshoe shapes on the empty Salisbury Plain, is, at the age of 4,000 years, one of the oldest, and certainly best preserved, megalithic (ancient stone) structures on Earth. It is a fantastic creation with the larger 25-ton Sarsen (a hard type of sandstone) stones transported from a quarry 18 miles away. Some of these boulders also carry massive lintels connecting them. In ancient times, when all the stones were standing, there was a ring of rock in the sky as well as on the ground.