noun
natural monument
A natural feature or area designated for protection under Japanese law, such as a geological formation, ancient tree, or habitat.
この巨木は国の天然記念物に指定されている。
This giant tree is designated as a national natural monument.
noun
protected species; protected habitat
Used for animals, plants, or habitats legally protected as natural monuments; often appears in news and conservation contexts.
その鳥は天然記念物なので、捕まえてはいけない。
That bird is a protected species, so you must not catch it.