Precolonial settlements varied according to region. In the Rif, local communities ( dshur ; sing. dshar ) consisted of highly dispersed individual homesteads, one-floored, flat-roofed structures of mud and stone, with rooms formed around a central courtyard. Each was at least 300 meters from the next and housed either a large nuclear family or an extended one of father and married sons or of brothers and their wives and children. Since the 1970s, however, owing to unprecedented labor migration to Western Europe, the Rif has become "urbanized," with apartment-type buildings now studding the countryside. In the Central Atlas, local communities ( timizar ; sing. tamazirt ) consisted of three or four fortlike structures called qsur (Arabic; sing. qsar ) or igharman (Tamazight; sing. igharm ). Made of adobe and stone, these structures stood three or four stories high. Each had a central courtyard and internal staircases leading to individual rooms of the various nuclear families ( tashat ; pl. tashatin ) comprising the several patrilineages ( ighsan ; sing. ighs ; lit., "bone") that constituted the tribal section ( taqbilt ; pl. tiqbilin ). The igharman were generally named after one of the sections, and these names were usually replicated in other localities. Imazighen who take their sheep on transhumance up into the Atlas in spring live in black goat-hair tents while pasturing them during the summer in special reserves called igudlan (sing. agudal ), which have rigid opening and closing dates and which are usually owned exclusively by the group in question. The Imazighen return to their permanent igharman in the fall for agricultural operations. The villages ( l-mwada' ; sing. l-muda' ) of the Ishilhayen show features combining the Central Atlas igharman with Rifian-type homesteads in the lower areas and compact Kabyle-type villages in the higher ones. Collective store-houses ( agadir ; pl. igudar, but also igharm), still to be found in the Central Atlas, also existed in this area but were abandoned during the colonial period.