A natural monument is a natural or natural/cultural feature of outstanding or unique value because of its inherent rarity, representative of aesthetic qualities or cultural significance. Natural monument sign in Heiligengrabe-GlienickeNatural monument sign in Gran Canaria A natural monument is a natural or natural/cultural feature of outstanding or unique value because of its inherent rarity, representative of aesthetic qualities or cultural significance. Under World Commission on Protected Areas guidelines, natural monuments are level III, described as: