Among the Kenyah, the village consists of one longhouse. Among the Kayan, a village (which may have from 30 to 1,148 inhabitants) consists of a group of longhouses. Each village has a section of river as its own territory. As a result of soil degradation, a village will move along the river, returning after 12 to 15 years. The Kayan longhouses are impressive for their size and durability. They are raised on pilings (originally as part of a defense strategy), are constructed of ironwood planks, and may be as long as 300 meters; they may house 500 people each (although the average is 200-300). Each family owns the planks and beams that make up its part of the longhouse. Unmarried older boys and men sleep on the veranda, while unmarried girls, women, and female slaves live with their respective families.