they show elevation using contour lines – in simplistic terms a contour line is a line
which joins points of equal elevation above sea level;
• they have an emphasis on showing human settlement (roads, cities, buildings etc),
but may include some thematic information such as vegetation or the boundaries of
national parks;
• they are typically produced by government agencies – these are often specialist
mapping agencies and may have either a civilian or defence purpose;
• they have well defined standards (called Specifications) which are strictly adhered
to – these vary between mapping agencies and the scale of the map;
• they have very good location reference systems – including latitude and longitude,
but may also have grid lines;
• often have additional information such as an arrow pointing to Magnetic North as
well as True North;