The orienteering map has evolved substantially over the last 50 years. In the 1940s, events in Scandinavia used 1:100,000 (1 cm =1 km) government issue maps, often in black and white and without contour lines to show the shape of the land. Nowadays, most orienteering events are held on five-color maps that have 5 meter contour intervals (16.5 feet) and have a scale of 1:15,000 (preferred) or 1:10,000 (1 cm = 100 meters).
Most of the characteristics of orienteering maps are related to those found on hiking and general use maps produced by the government. However, one feature of orienteering maps is specific to the sport: the north lines. On the example shown here, they are drawn in blue (on many maps, they are black). North lines are parallel lines drawn running from magnetic south to magnetic north, and are spaced 500 meters apart on the map. Why aren't north lines on orienteering maps drawn pointing to true north? Because the angle between magnetic north and true north (the declination) varies widely in different parts of the world, and because orienteers use compasses to orient themselves (to magnetic north, not true north), it has become the standard to provide a series of reference lines on the map so that it is easy to use an orienteering compass to take a bearing.
There are international specifications for map symbols, and these have been successful in their aim of making orienteering map symbols standard throughout the world.
Some general rules for orienteering map symbols that make the system easier to understand.