seinämiä

Could you clarify what you mean by "seinämiä"? The term could refer to different things in Finnish, such as a linguistic form (a plural/partitive form related to words meaning wall or wall surfaces) or potentially a place, organization, or cultural concept. Once you specify the intended sense (e.g., architectural term, geographic location, or another usage), I can write a concise, neutral wiki-style article under 300 words.