At higher elevations, as on the plateau straddling Guizhou and Yunnan, settlements are rarely larger than twenty households. An average village in central Guizhou might have 35 or 40 households, while in Qiandongnan villages of 80 to 130 families are common, and a few settlements have close to 1,000 households. Villages are compact, with some cleared space in front of the houses, and footpaths. In some areas houses are of wood, raised off the ground, and with an additional sleeping and storage loft under a thatched or tiled roof. Elsewhere they are single-story buildings made of tamped earth or stone depending on local conditions. Windows are a recent introduction. Animals are now kept in outbuildings; in the past they were sheltered under the raised house or kept inside. Many settlements are marked by a grove of trees, where religious ceremonies are held.