Naturalistic surfaces for floors and ground are made of materials as they occur more or less naturally, whether found in situ or re-formed by human construction.

Human placement or maintenance does not by itself exclude a surface. A layer of loose natural material can be brought to the site and arranged for walking or recreation while retaining the character of that material.

The surface material determines the more specific choice. Loose wood pieces differ from joined wood boards, and loose earth differs from a manufactured tile or slab made from earthen ingredients. The use of an area does not by itself identify its ground covering.