Natural burial is the interment of the body of a dead person in the soil in a manner that does not inhibit decomposition but allows the body to be naturally recycled. It is an alternative to typical contemporary Western burial methods and modern funerary customs. The body may be prepared without chemical preservatives or disinfectants such as embalming fluid, which are designed to inhibit the microbial decomposers that break the body down. It may be buried in a biodegradable coffin, casket, or shroud. The grave does not use a burial vault or outer burial container that would prevent the body's contact with soil. The grave should be shallow enough to allow microbial activity similar to that found in composting. Natural burial grounds have been used throughout human history and are used in many countries. Natural burial has been practiced for thousands of years, but has been interrupted in modern times by new methods such as vaults, liners, embalming, and mausoleums that mitigate the decomposition process. In the late 19th century Sir Francis Seymour Hayden proposed "earth to earth burial" in a pamphlet of the same name, as an alternative to both cremation and the slow putrefaction of encased corpses. Natural burial grounds employ a variety of methods of memorialization. Families that bury their loved ones in nature preserves can record the GPS coordinates of the location where they are buried, without using physical markers. Some natural burial sites use flat wooden plaques, or a name written on a natural rock. Many families plant trees, or other native plants near the grave to provide a living memorial. While natural burials tend to prevent the environmental damage done by conventional techniques, some practitioners go further by using burial fees to acquire land to restore native habitat and save endangered species. Such land management techniques are called "conservation burials". In addition to restoration ecology, and habitat conservation projects, others have proposed alternative natural uses of the land such as sustainable agriculture and permaculture, to maintain the burial area in perpetuity.