The Poly Object can be used to capture admin borders, as well as natural areas, such as lakes, or parks.
Any area that is not specifically an admin border, is called a Muli polygon with OpenStreetmap. These are handles differently, but the Poll Object still lets you get these areas.
- in the Poly Object Settings, you can set a search query. This can be as simple as "natural" or "water", but you can also do complex query's.
- This article.. gives you detailed Information on what a query might look like.