The bulk of the Wolof, about 70 to 75 percent, are rural villagers; the remainder constitute an important element in many of the larger urban centers of Senegal and in the Gambian capital of Banjul. The average size of Wolof villages tends to be quite small, with a mean population range of about 50 to 150, but up to 1,000 or 2,000 people inhabit some political centers. Most Wolof villages have one of two types of settlement plan: a village consisting of two or three separate groups of residential compounds with no central focus, or a nucleated village with the residential compounds grouped around a central plaza, where a mosque is usually located. In either type of village, compounds generally consist of square huts (traditionally round, as is still true in Gambia) with walls made of millet stalks or banco (an adobelike material), and conical, thatched roofs. In addition, there are several small cooking huts, storehouses, and animal shelters, all enclosed by a millet-stalk fence. More affluent villagers may have one or more modern, multiroom, rectangular houses constructed of cement blocks with tile or corrugated tin roofs. Many Wolof villages have an attached hamlet or encampment of Fulbe who "belong" to the village and herd their cattle.