OS Map Symbols – Unlocking the Code
A map is a graphic, two-dimensional visualisation of the world around us. The first Ordnance Survey (OS) map was published in 1801, but the first OS map symbols did not appear until 1886, when they were used to illustrate trees and vegetation.
Nowadays OS maps use a wide variety of symbols to help us represent (and make sense of) the world around us. OS symbols help the map reader to understand what appears on the map and are a useful guide to what you can expect to see when you’re out and about exploring the UK.
They can represent an environment in extraordinary detail. For example, they can show whether a piece of woodland is composed of deciduous or coniferous trees, and reveal the character of the ground you will cross – very useful to avoid muddy and marshy areas on your walk.
Why use map symbols?
OS maps use symbols that label real-life features and make the maps easier to understand. With so many features on an OS map, there just wouldn’t be enough space to label everything with text, meaning the map would become very cluttered and difficult to use.
Using symbols on a map can be a clever way of avoiding this. They can be small pictures, letters, lines or coloured areas to show features like campsites, pubs or bus stations. If you look closely at a map, you will see that it is dotted with these symbols throughout.
You will find a legend or key printed at the side of every map that lists all of the symbols used. Even if you know the area well, you may even discover features on the map that you’ve never realised were there when you passed close by on foot or by car!
Different kinds of symbols
OS map symbols are used to represent three basic types of information, known as point data, line data and polygon data.
Point data is exactly what it says
It is a single location point within the map. For example, this could be a car park, a viewing point or a trig pillar. You can read more about trig pillars here. These are usually represented by the following shapes or symbols:



Line data
This is used to represent symbols containing lines, such as:





Polygon data
This is used to represent specific area features within the map, such as water, woodland or sand. These areas are then usually filled with specific colours to differentiate them and help them to be identified easily.



Updating map symbols
OS symbols are refreshed regularly to reflect the changing environment in which we live. For example, in 2015 six new symbols were introduced for electric car charging points, art galleries, solar farms, skateboard parks, toilets and kite surfing areas.
These new symbols were chosen by a competition that was open to members of the public to design and submit their ideas for the symbols.
An OS map symbol is the easily understood map language that will guide you through every walk, bike ride or run that you go on. All of the features you will see when out and about are on your OS map, and the symbol will help you with your map reading and to understand what your map is telling you.
And if you’re planning a walk this post on how to plan a walk with an OS map is a useful read
Now you know more about OS map symbols, perhaps you could come up with an idea for a new map symbol ready for when the next refresh takes place?
Map and Map Symbol images are subject to © Crown copyright. All rights reserved.
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