Though Britain contains within itself all the materials necessary for building, it is probable the ancient inhabitants lived in holes and caverns of rocks, or formed themselves huts, which they covered with turf supported by branches of trees bound together with twigs of ozier. In after-ages, when commerce brought the Phoenicians and other civilized nations acquainted with them, they learned from those strangers many useful arts. But their habitations, according to Caesar, were in his time little improved, their towns were only a confused parcel of huts, placed at a little distance from each other, without order or distinction of streets; they generally stood in the middle of a wood, the avenues whereof were defended with slight ramparts of earth, or with trees that had been felled to clear the ground.