alikäyrillä

Could you clarify what “alikäyrillä” refers to? Is it a real place in Finland (or elsewhere), a geographic feature, a historical term, a concept in a field, or a fictional concept? If you can provide the intended context (location, region, purpose, or whether it’s fictional), I can write a concise, neutral wiki-style article in Finnish (under 300 words). If you’d prefer, I can also create a generic stub that outlines possible meanings without asserting specific facts.