The purpose of this riddle is to puzzle you and draw your attention to the missing items, which are the buildings, trees, and fish.
You might guess you need to think about something inanimate.
You are a Map.
A map is a representation of an area, a country, on a flat surface or chart.
Cities are shown on a map as lines, but a map does not have houses.
Mountains with contours can be seen on a map, but it does not show tress.
A map can also show the location of a lake, river, sea, or ocean, but it does not show a fish.