One of the most common types of construction in Morocco was rammed earth, an ancient building technique found across the Near East, Africa, and beyond. It is also known as "pisé" (from French) or "tabia" (from Arabic). The ramparts of Fes, Marrakesh, and Rabat, for example, were made with this process, even though some notable structures (like monumental gates) were also built in stone. It generally made use of local materials and was widely used thanks to its low cost and relative efficiency. This material consisted of mud and soil of varying consistency (everything from smooth clay to rocky soil) usually mixed with other materials such as straw or lime to aid adhesion. The addition of lime also made the walls harder and more resistant overall, although this varied locally as some areas had soil which hardened well on its own while others did not. (For example, the walls of Fes and nearby Meknes contain up to 47% lime versus around 17% in Marrakesh and 12% in Rabat.) The technique is still in use today, though the composition and ratio of these materials has continued to change over time as some materials (like clay) have become relatively more costly than others (like gravel).