Planimetric map from the 1901 British Ordnance

http://www.hatheway.net/03_gas_plant_components.htm

Planimetric maps are two-dimensional maps or surface maps that contain no relief features much like a street map. These type of maps are only concerned with the horizontal positions of features and are not concerned with elevation. This style of map is also known as a line map. The above map shows the area encompased by an early "gas works". It also shows its position in relation to other geographic phenomena, roads, and buildings. This is basically an early form of a type of survey map.

Mental Map of the World

http://andrewshears.wordpress.com/2010/12/19/mapping-geo-autobiography-my-mental-map-of-the-world/

This map is a prime example of a mental map. Mental maps are created based on the day-to-day experiences or percieved reality of the person(s) who created the map. They are used to communicate particular geographic relationships based on the experience of an individual or group of persons. The above mental map attempts to show a mental translation of the authors percieved perception of the world. The map and/or process of mental mapping can show that the idea that mental maps are not 100% acurate to the real world.