Strict taboos on harvesting trees and other plants exist. This has meant that, even though the groves are small, in many cases these sites are the only areas where forest remains. They represent sanctuaries for both plant and animal species. They contain mature indigenous trees, many of which quite rare in the area, and are particularly rich in bird and mammal life. In many cases, the groves are associated with a cave and anatural spring or well. These provide healing waters, as well as dry seasonwater source for people and livestock. The groves are also an important source of medicinal plants, and are used for healing. However, rapid urbanization has meant that forests are under severe pressure for fuel wood and building material. Significant pressures also come from Zanzibar’s tourism industry, with both small-scale and larger beach-based tourism establishments encroaching on the sacred sites. Intergenerational social changes, new immigrant populations, and exposure to cosmopolitan values through tourism have led to declining social respect for the sites. Several of them have been damaged, and many are at risk.