of the old cities, such as the Bab Bou Jeloud gate in Fes (completed in 1913) and the nearby Collège Moulay Idriss (opened in 1914). The new French-built cities also introduced more modernist styles such as Art Deco. This heritage is especially notable in Casablanca, which became the main port city and the country's largest city during this period. Constructions methods and materials Rammed earth (pisé) 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."Pisé", in The Penguin Dictionary of Architecture and Landscape Architecture, 5th edition (1998). p.439 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).The walls were built from bottom to top one level at a time. Workers pressed and packed in the materials into sections ranging from 50 and 70 cm in length that were each held together temporarily by wooden boards. Once the material was settled, the wooden restraints could be removed and the process was repeated on top of the previously completed level. This process of initial wooden scaffolding often leaves traces in the form of multiple rows of little holes visible across the face of the walls. In many cases walls were covered with a coating of lime, stucco, or other material to give them a smooth surface and to better protect the main structure. This type of construction