Maps are simply an accurate picture of the ground as seen from above, scaled down from life size, and with symbols to show particular features and landmarks. If want to plan your own routes or walk one of our many walking routes available online, our easy guide will get you started.
To measure the approximate distance of your route, take a piece of thin string and lay it carefully along the exact route on the map, then lay it straight along the scale line on the map’s margin. With practice, you’ll soon learn to estimate the distances involved by eye, but don’t forget the extra effort of climbing hills when calculating how long the route will take to walk.
Contours are lines connecting points of equal height above sea level that show the relief of the land. Together with spot heights, they portray the shape of the landscape, its height, the form taken by hills and valleys, the steepness of slopes, and so on. On OS Explorer maps, the interval between contours is five metres in lowland areas and 10 metres where mountainous. At random points along many of the contour lines a number is shown to indicate its height, always printed so that the top of the number points uphill. Every fifth contour line is printed more thickly than the others. The closer together contours are, the steeper the ascent or descent for the walker.
Spot heights – shown as a number beside a dot – appear at strategic points, including along roads where they level out at the top or foot of a hill. These can be a useful guide where there aren't many contour height numbers.
All OS maps are criss-crossed by vertical and horizontal grid lines (coloured blue on OS Explorer maps) which are 4cm apart on 1:25,000 scale maps and 2cm apart on the 1:50,000 scale. A grid reference uses six figures to identify a particular spot on a map that is 100 metres square. The first three specify the vertical lines (the eastings) and the second three the horizontal (the northings).
So with the grid reference TQ303782, TQ indicates the 100 sq km of Britain designated by Ordnance Survey’s National Grid as ‘TQ’, and the location is 30 squares and three tenths east and 78 squares and two tenths north. Sometimes four-figure grid references are used to give a rough location that covers the map grid square, not a specific point within it.
What is the grid reference of the church in the example above?
To find a point on a map using a six-figure grid reference, simply do the reverse. Remember to start with the eastings (the first three figures) and then move up the northings (the last three). A helpful reminder is the saying: ‘go along the corridor and then up the stairs’.
Now you know how to read a map, why not find a walking route near you to walk?
Ordnance Survey has some useful guides to reading maps on their website:
Photo: Thomas Abbs