A survey of the natural features of the land, as well as improved areas that determine the horizontal and vertical relationships, and show grades or contours, and all improvements and utilities. Topographic Surveys are used to identify and map the ground and existing features on the surface of the earth or slightly above or below the earth's surface (i.e. trees, buildings, streets, walkways, manholes, utility poles, retaining walls, etc.). The purpose of the survey is to serve as a base map for the design of a residence or building of some type or design a road or driveway, it may be necessary to show perimeter boundary lines and the lines of easements on or crossing the property being surveyed, in order for a designer to accurately show zoning and other agency required setbacks. Topographic Surveys require "benchmarks" to which ground contours are related, information regarding surface and underground utilities, determination of required setbacks, etc.