Mountain Navigation: Maps, Symbols and Scales


In this the first part of our mountain navigation series, we cover the different map sources available to UK users and the scales and symbols used on them.

Map Sources

There are a wide variety of sources of maps which can be used for navigation in the United Kingdom. 


Online resources like Google Maps and Multimap, while great for planning roadtrips, don’t really cut it when it comes to navigating in the hills.  Although Multimap uses Ordnance Survey (OS) data, the lack of detailed topology (the way in which geographical elements are related to each other) on Google Maps makes the later a definite non-starter.

In mountain navigation you not only need to be able to see information about your immediate area but also the wider area, sometimes many miles out.  This is essential when trying to use geographical features such as surrounding peaks and distant lakes to locate yourself on the map. 

This is where the online maps generally fall down.  Due to the limited area you can print out on a single sheet, a route could end up spanning multiple sheets of A4, which in driving rain and a gale could get quite confusing.


There are a number of handheld devices on the market that will display your location on a map and track your movement using GPS (global positioning system).  Although these can be very effective, they do take some of the skill, and some may say fun, out of mountain navigation. 

As with any electrical device you at the mercy of technical failure and GPS’s in particular are reliant on good satellite coverage and can eat batteries fast.  The use of GPS systems while increasingly popular, should not be seen as a substitute to a good basic knowledge of navigation using a paper map and compass.

We will cover the use of GPS’s in more detail, later in this series.

Paper Based

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Historically the Ordnance Survey were the primary provider of paper based maps in the UK and are the only provider to cover the entire country in various scales.  In recent years Harveys Maps has produced a number of solutions aimed at popular walking and climbing locations around the country.  These have become very popular and many find their different symbols, colour schemes and contour systems much clearer.

In partnership with the BMC, Harveys Maps have also just launched as series of maps primarily focused on the UK National Parks.  These include a single map covering the popular walking areas in the Lake District, something which requires four explorer or two landranger maps from Ordnance Survey.  Further details of which can be found on the BMC website.

Computer Based

The final option are solutions such as Memory Map and Tracklogs which provide software to allow you to plan your routes on your PC or Mac at home.  These can then be printed out using ordnance survey map data or even uploaded to your GPS for use while out on the hill.  Finally you can also download a route you have recorded on your GPS and overlay on a map.

There are many benefits to this system over traditional paper based maps.  Firstly you only need to print out the area you require and you don’t have the complication of carrying multiple maps when a route goes from one map to another.  Also, as you can print a fresh copy of the map each time you walk in an area, you don’t have to worry about replacing your maps after it starts to suffer wear and tear.

Although the initial cost of purchasing such a system may be higher than buying single map, in the long run you are likely to be better off and appreciate the flexibility these systems offer.

UK Maps

For the benefit of this series we will focus on the ordnance survey maps, as these provide the widest coverage and are used by both Memory Map and Tracklogs

As previously mentioned, the Ordnance Survey (OS) are the only publisher to produce maps covering the entire country.  The UK is broken down into a number of different sheets, which overlap slightly to make it easier when moving from one sheet to another.

There are a number of different series of maps, each printed using a different scale.  The most popular for navigating in the hills are the Landranger and Explorer series.  Each cover the entire country with the Landranger series (204 maps in total) using a 1:50,000 scale (more commonly referred to as 1:50 or 1 to 50) and the Explorer series (403 maps in total) using a 1:25,000 scale (1:25 or 1 to 25).


The scale of the map describes how distance on the map relates to the physical distance on the ground.  Put simply, when working on a 1:50 map, 1cm on the map equates to 50,000cm or 500m on the ground. Similarly 1cm on a 1:25 map equates to 250,000cm or 250m on the ground.  This is important when judging distance or planning routes, something which we will come onto in more detail later in the series.

From OS’s perspective, this means that on a 1:25 map they have 4cm squared of paper to display a square kilometer, in comparison to only 2cm squared on a 1:50 map.  This gives them four times as much space on a 1:25 map, allowing them to include much more detail such as field boundaries or buildings. 

This can be extremely useful when trying to pin point your position and is the reason why the Explorer 1:25 maps are the number one choice for many hill walkers.


All maps, not just Ordnance Survey, use a series of symbols and colour coded lines to represent roads, paths, buildings, services and other geographical features on the map.  Although many of these will be common from map series to series, there are sometimes differences, especially with the use of colour.

To aid the user all maps come with a handy key giving the meaning of each symbol used.  If you are not familiar with a particular map, or if it has been a while since you have used one then I would encourage you to take a few minutes to review the key prior to starting out on a route.

Since the change in access laws, the Ordnance Survey has updated its Explorer maps to clearly show areas where the public has a right to roam.  This is especially important in England where unlike in Scotland, we don’t have the right to roam across all open land.  In addition to this, if you are a mountain biker it is essential that you can recognise the difference between a footpath and a bridleway on a map in England as you shouldn’t ride your bike along public footpaths.

About the Author

Written by Giles Thurston, a qualified International Mountain Leader with over twenty years of experience of navigating in a mountain environment, including working as an outdoor instructor teaching navigation.

Further Reading

There are many books available which could provide further useful reading on the subject of mountain navigation.  Some of the best are listed below:

Map and Compass - The art of navigation

By Pete Hawkins and published by Cicerone Press

The art of navigation from first stages to GPS. For everyone from the complete novice to the experienced hillwalker. Explanations on the different type of tools available to help in finding your way. Fully illustrated with the author’s own photographs and OS and other mapping. Appendices outlining further practice techniques and useful sources of information.

Navigation - Techniques and skills for walkers

By Pete Hawkins and published by Cicerone Press

This practical guide will help you get the most out of your map and give you the key skills to using your compass. It’s then down to you. Practice will make perfect, and with that will come the freedom and confidence to enjoy our hills and mountains.

Navigating with a GPS - Effective skills for the outdoors

By Pete Hawkins and published by Cicerone Press

This practical guide explains how to get the best from your GPS, and takes you through GPS navigation in a clear and structured way. It summarises how to navigate with a map and compass. The guide also looks at digital mapping, and how GPSs and mapping software can be used positively together.

Article written by Giles Thurston on August 18, 2008


Posted by Liz on March 25, 2009

HI… could you tell me the answer to this question that I can’t find the answer to… What is the symbol on the 1:25” scale maps (of old Iguess) that looks like a stretched letter “S"… it also looks like a mathematical integral symbol apparently!  It appears several times on this scale map, but is not noted what it stands for.  Any help you can give wil be appreciated… Many thanks… LIz Morgan

Posted by connor duffy on May 19, 2009

love it

Posted by soham on April 13, 2010

this is a very useful info.. but truly speaking until or unless someone is teaching u these things, u won’t b able to find a single place in the mountain… it’s very true. i have read some books in mountain rescue. but when i had gone for mountaineering course, then only i course understand how tough is that....

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