Murus gallicus
Murus gallicus or Gallic wall is a method of construction of defensive walls used to protect Iron Age hillforts and oppida of the La Tene period in Western Europe. == Basic features == The distinctive features are: earth or rubble fill transverse cross beams at approximately 2 ft (60 cm) intervals longitudinal timbers laid on the cross beams and attached with mortice joints, nails, or iron spikes through augered holes outer stone facing cross beams protruding through the stone facing == Technique and utility == The technique of construction and the utility of the walls was described by Julius Caesar in his Commentaries on the Gallic War: But this is usually the form of all the Gallic walls.