There are certain types of megalithic buildings. The term 'megalith' is Greek and means big stone. The two major classes of megalithic buildings are: Chamber-tombs and standing stones.
Standing stones can be found solitaire as menhirs, or as stone rows or stone circles. Menhirs or single stones can be found in many places, whereas stone rows are found mainly in Brittany, the most famous of which are the alignments of Carnac. Stone circles in some form are found in many places, for example as perimeters of mounds. In Britain however, a high number of stone circles have evolved to be stand-alone monuments. The most famous examples include Stonehenge and Avebury.
The meaning of standing stones is still not known, but it seems to be likely that their purpose is connected to ritual activities related to the ancestors. Stone circles are also discussed as astronomical and calendar tools.
Chamber-tombs can be found all over the world (see Joussaume). In Europe most megalithic tombs are concentrated along the 'Atlantic facade' from Portugal and Spain to the north of France, the British Isles over to Holland and North-Germany to Scandinavia. The findings of human remains in many tombs prove that they were used for burials and for some form of ritual activities related to honour the ancestors.
It is worth mentioning that wooden structures played an important role in Neolithic times, but they were mainly destroyed over time. In Britain for example it is likely that in the eastern areas wooden and earthen structures were build for burials and were indeed a precursor for the megalithic buildings in many places. Further wooden structures and oval or circular palisades were erected for ritual purposes together with stone circles, like the Sanctuary near Avebury or Woodhenge and Durington Walls next to Stonehenge.