Definition of Map Legends in Geography

Map Key Definition

A map key is an inset on a map that explains the symbols, provides a scale, and usually identifies the type of map projection used. Technically, the key is part of the map legend. The key explains the symbols while the legend holds the key and other information.

Purpose Of A Map Key

The purpose of a map key is to tell you the meaning of the symbols on a map. The key on a map interprets each symbol so that you can read and understand the map.

For example, what does this symbol, ⇞, mean? Is it important to know what it means? Is it pointing in a direction, standing for a single tree, or indicating a forest?

The map key is the only way for you to know for sure what the above symbol means.

Table of Contents

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1. Definition
   • Purpose
2. Symbols
3. Legend Vs. Key
4. Examples
5. Compass Rose

Map Key Symbols

When making a map, Cartographers (map makers) cannot write out everything and make it fit. They need quick, simple drawings, called map symbols, to replace written information. If you do not know what $·$, $\circ$, or $\odot$ means, you cannot understand the map.

A map key tells you what all the symbols on the map mean. For example, the small black dot, $·$, means a town or village, the open circle, $\circ$, means a city of at least 75,000 people or that $\odot$ means a state capital. A map key can tell you that ★ usually shows a country's capital.

Every map uses its own map symbols, depending on the information the cartographer wants to show. Map keys can show symbols for natural resources, population centers, bodies of water, types of industry, and much more.

Here are some different symbols appearing in map keys:

Types Of Map Symbols

Symbol	Meaning
	River
	Railroad Tracks
	Food
	Bar
	Cafe
	Shopping
	Grocery
	Arts
	Lighthouse
	Theater
	Tourist Attraction
	Casino
	Aquarium
	Event Venue
	Amusement Park
	Historical Site
	Museum
	Movie Theater
	Monument
	Music
	Relic
	Gas Station
	Parking
	Car Rental
	Hotel
	Resort
	ATM
	Bank
	Hospital
	Pharmacy
	Medical
	Park / Forest
	Mountain
	Sports Stadium
	Zoo
	Campground
	Cemetary
	Golf Course
	Garden
	Hiking
	Boating
	Fishing
	Airport
	Train
	Metro
	Subway
	Bus
	Rail
	Ferry
	Bridge
	Civic Building
	Post Office
	Library
	Police Station
	School
	Restroom / Bathroom
	Miscellaneous
	Church or Temple
	Synagogue

As you see in this list of Google Maps symbols above, different colors represent different categories. Green for outdoors, orange for dining and drinks, etc.

Map Key Examples

This map of Tennessee has a key that shows how the land is used. Tiny symbols that look like pigs, plants, and stone show where animals are raised for food, where plants are grown, and where ores and rocks are mined.

This map key uses natural colors for natural formations but uses abstract shapes for human activity. It uses coded squares to show ruins and archeological sites. It uses circles to stand for villages and towns. The natural formations such as ice and desert are shown in colors that resemble the real things.

Legend Vs. Key

You may wonder what the difference is between a map key and a map legend. The key makes the map understandable. The map legend usually includes not only the map key to the symbols but a lot of other useful information:

• Map scale, in large units like miles and kilometers, or small units like feet and meters
• Map projection name, like Mercator, Cassini, Equirectangular, Gauss–Krüger, or Sinusoidal
• Map publication date
• Cartographer or company name

Today we use both phrases to mean the same thing, but the map key is technically found in the map legend.

Compass Rose On A Map

The compass on a map is called a compass rose. Its main function is to point north, but it almost always shows the cardinal directions (north, south, east, and west). Sometimes it tells the intermediate or ordinal directions, too: northeast, southeast, northwest, southwest.

Unlike all the other symbols on the map, the compass rose does not usually appear in the key or legend. It is usually drawn in an unimportant area, like an ocean or vast desert, so that it does not cover locations. By tradition, most maps orient so that north is at the top of the map.

On maps and nautical charts dealing with tides, sailing, and coastlines, the compass rose is also called a "windrose" or "rose of the winds." Highly accurate nautical charts and some topological maps show both true north and magnetic north on the compass rose.

Map Key Quiz

See if you can find your way around a map by answering these questions.

1. Define the "map key."
2. What is another name for a legend on a map?
3. Why is a legend necessary for most maps?
4. What symbol is next to Washington DC on the map?

[insert copyright-free version of U.S. map such as this one with Washington, DC starred from https://geology.com/world/the-united-states-of-america-satellite-image.shtml]

1. What does a star usually mean on a map?
2. Fill in the blank: a map's ___________ explains its markings and symbols.
3. What map symbol for a mountain range is most often used?

The key to becoming a legend in your own time is to study hard. Don't peek at the answers below until you have tried your best!

1. You might define "map key" as the part of a map inside the map legend that tells what the map symbols mean. We use a map key and map legend interchangeably.
2. Another name for a legend on a map is a map key, although you can get very picky and say that the legend holds the map key and other information.
3. A legend is necessary for most maps because cartographers cannot write everything into the map, so they need symbols. The symbols require a key to understand them.
4. The star symbol, ★, is next to Washington DC on the map.
5. A star, ★ , usually means a country capital on a map.
6. Fill in the blank: a map's legend or key explains its markings and symbols.
7. The map symbol for a mountain range is often a tiny triangle or upside-down $\vee$: $△$ or $\wedge$.

Definition of Map Legends in Geography

Source: https://tutors.com/lesson/map-key-definition-symbols-examples