Why paper maps still matter on a British walk

There is a particular pleasure in unfolding a paper map on a blustery fellside. The paper crackles, the wind tugs at the corners, and suddenly the whole landscape is laid out before you in contour and colour. Ordnance Survey maps remain the gold standard for exploring footpaths and bridleways across the United Kingdom. A charged phone can fail, a signal can vanish, but a map and compass will keep you on track. Learning to read one properly transforms a walk from a simple stroll into a conversation with the countryside.

Understanding grid references: eastings and northings

Every OS map is covered by a grid. The lines running vertically are eastings, and those running horizontally are northings. Each grid square represents one kilometre on the ground. On an Explorer map (1:25,000), that square is 4cm across; on a Landranger (1:50,000), it is 2cm.

To give a grid reference, you quote the two letters of the 100km square, then the easting, then the northing. A six-figure reference like SU 123 456 pinpoints a spot to within 100 metres. Always read along the corridor and up the stairs: eastings first, then northings. On a 1:25,000 map, you can estimate tenths of a grid square for a more precise eight-figure reference. Practise by finding a familiar landmark, such as a church tower or a trig pillar, and noting its reference.

Contours: reading the shape of the land

Contour lines join points of equal height. The vertical interval is usually 10 metres on OS maps, so each line represents a climb or descent of ten metres. The closer the lines, the steeper the slope. Widely spaced contours mean gentle ground; tightly packed lines mean a sharp pull up or a precarious descent.

• V-shaped contours point uphill when they cross a valley. The point of the V aims upstream, towards the source of the stream.
• Ring contours that close on themselves show a hilltop or a hollow. A small ring inside a larger one indicates a summit.
• Hachures (short lines radiating down a slope) mark a depression or a steep drop, often a quarry or a crag.

Reading contours lets you plan a route that avoids unnecessary climbing. A path that follows a contour line around a hillside is far easier than one that cuts straight up the fall line. Look for natural corridors: valleys, ridges and cols (the low point between two peaks) often provide the most rewarding walking.

Decoding the symbols: footpaths, bridleways and rights of way

OS maps use a rich vocabulary of symbols. The most important for walkers are the rights of way. On Explorer maps, public footpaths are marked with green dashes; bridleways have green dashes interspersed with small plus signs. On Landranger maps, these are shown in red. A byway open to all traffic is a green cross-hatched line, while a permissive path is marked with orange dashes and is not a public right of way.

Other symbols to watch for:

• Walls and fences are black lines; gates and stiles are shown as small symbols. A broken line may indicate a ruined wall.
• Streams and rivers are blue lines. A stream that disappears into a contour ring may indicate a spring or a sinkhole.
• Marsh and bog are shown with blue tufted symbols. These can be treacherous after rain.
• Crags and screes are marked with black hachures or shading. They are best avoided in poor visibility.
• Tumuli, cairns and standing stones are marked with antiquarian symbols, adding a sense of heritage to your walk.

Always cross-check a footpath symbol with a gate or stile. A path that ends abruptly at a field boundary may be a dead end or a mapping error. Use the map alongside a guidebook or local access land information.

Putting it together: pacing, handrails and map orientation

Before you set off, orient the map. Use a compass to align the grid north with magnetic north (accounting for magnetic variation, which is currently around 1–2 degrees west in the UK, but check the map margin). Alternatively, match the map to the landscape: find a distinctive hill, church spire or bend in a river, and rotate the map until it lines up.

As you walk, use handrails—linear features like walls, streams or forest edges—to guide you. Count your paces to estimate distance: on average, 100 metres is about 125 double paces, though this varies with terrain. Time is another check: a fit walker covers roughly 4–5 kilometres per hour on flat ground, plus one minute for every 10 metres of ascent (Naismith's rule).

Keep your thumb on the map at your current location. Fold the map so you only see the relevant section. If you become unsure, stop, reorient, and look for a feature that matches a symbol. A trig pillar, a ford, a footbridge—these are your anchors. With practice, the map becomes a story of the land, and every walk becomes richer for it.