Luonnonharja

Could you clarify what Luonnonharja refers to? I want to ensure the article is accurate. Is it:

- a plant or animal species,

- a geographic place or feature in Finland,

- a cultural term or concept,

- or a fictional/ hypothetical subject?

If you’d like, I can also draft a neutral, concise wiki-style stub assuming a specific category (for example, a Finnish place or a natural feature) and tailor the content to be under 300 words. Please provide the intended context or allow me to create a fictional encyclopedic entry.