Masquerade, metalwork, sculpture, architecture, fiber art, and dance are important art forms across Africa and may be included in the study of African art. The term “African art” does not usually include the art of the North African areas along the Mediterranean coast, as such areas had long been part of different traditions. For more than a millennium, the art of such areas had formed part of Berber or Islamic art, although with many particular local characteristics. The art of Ethiopia, with a long Christian tradition, is also different from that of most of Africa, where traditional African religion (with Islam in the north) was dominant until relatively recently. African art includes ancient art, Islamic art of West Africa, the Christian art of East Africa, and the ritualistic art of these and other regions. Most African sculpture was historically in wood and other natural materials that have not survived from earlier than, at most, a few centuries ago; older pottery figures can be found from a number of areas. Masks are important elements in the art of many peoples, along with human figures, often highly stylized. There is a vast variety of styles, often varying within the same context of origin depending on the use of the object, but wide regional trends are apparent; sculpture is most common among “groups of settled cultivators in the areas drained by the Niger and Congo rivers” in West Africa. Direct images of deities are relatively infrequent, but masks in particular are or were often made for religious ceremonies; today many are made for tourists as “airport art”. Since the late 19th century there has been an increasing amount of African art in Western collections, the finest pieces of which are now prominently displayed.