You can define one or more polygons (shapes on a map), and these polygons will define which listings display on a page. The page can display a map, or just listings with no map.
See Polygon search for more information.
By default, these polygons are drawn on the map. If you want the polygons to not appear on the map, you can add another parameter to suppress the display of the polygon, even while the polygon will still define the listings that appear on the page.