Raising a menhir: a 19th century artist's impression (note the total lack of technical expertise!).

Megalithic monuments are built with various materials : 

  •   earth and stone in the earthworks,
  •   small stones used for drystone masonry (sometimes arranged in sophisticated patterns),
  •   megalithic blocks (very difficult to handle),
  •   timber for technical purposes on the building sites (tools, scaffolding, rollers) or to build certain structures (roofing of some very large chambers or "megaxyls" completing or replacing menhirs). 

All these materials had to be: 

  •   supplied (stone had to be extracted or collected and trees had to be cut),
  •   transported (over distances from a few metres up to several kilometres),
  •   and processed (placed, assembled and shaped).