Stonehenge is britain's most famous monument. It is a group of enormous stones situated on salisbury plain in the south of england. It was built between 2000 b.c. and 1400 b.c. and many of the original stone are still standing today.there are two main circles of stones, one inside the other. In the center, the stones are in a horseshoe shape around a central block. The whole monument is surrounded.by a ditch.