<P> Before the use of bricks , the Great Wall was mainly built from rammed earth , stones , and wood . During the Ming , however , bricks were heavily used in many areas of the wall , as were materials such as tiles , lime , and stone . The size and weight of the bricks made them easier to work with than earth and stone , so construction quickened . Additionally , bricks could bear more weight and endure better than rammed earth . Stone can hold under its own weight better than brick , but is more difficult to use . Consequently , stones cut in rectangular shapes were used for the foundation , inner and outer brims , and gateways of the wall . Battlements line the uppermost portion of the vast majority of the wall , with defensive gaps a little over 30 cm ( 12 in ) tall , and about 23 cm ( 9.1 in ) wide . From the parapets , guards could survey the surrounding land . Communication between the army units along the length of the Great Wall , including the ability to call reinforcements and warn garrisons of enemy movements , was of high importance . Signal towers were built upon hill tops or other high points along the wall for their visibility . Wooden gates could be used as a trap against those going through . Barracks , stables , and armories were built near the wall 's inner surface . </P>
what did they use to build the great wall of china
rammed earth stones wood bricks materials such as tiles , lime , and stone