Why the map earns its place in your pack

Moorland has a habit of looking honest on a clear morning and treacherous by two o'clock. The path in front of you is obvious, the cairn you passed twenty minutes ago seems reassuring, and then the cloud drops and every feature turns the same shade of grey-brown. Walking on open moor is one of the great pleasures of a smallholding life — a proper lungful of air, curlews calling, no fences telling you where to go — but it is also the terrain where a folded map in a plastic case counts for more than any gadget. Learn to read the land on paper and you will make good decisions long before the weather forces you to.

The good news is that a topographic map is not a puzzle. It is a picture of the ground drawn to a set of rules. Once those rules click, you can picture the shape of a hillside from your kitchen table as clearly as if you were standing on it.

Contour lines: the shape of the land

Contours are the thin orange-brown lines running in loops across the map. Each one joins points of equal height above sea level, and the vertical distance between them — the interval — is printed in the map legend. On the 1:25,000 leisure sheets covering most British upland it is usually 10 metres, with some areas at 5 metres for extra detail. On 1:50,000 sheets it is 10 metres throughout, which is why the larger scale is worth the extra bulk in a moorland pack.

Read them like this:

• Close together means steep ground. Very close, with black hachures or a crag symbol, means a drop you should not be walking off in mist.
• Far apart means gentle slopes, the kind that hide a bog.
• Loops pointing uphill into higher ground mark a re-entrant — a gully or a small valley. Water and often a faint path will be in the bottom of it.
• Loops pointing downhill mark a spur or ridge. These are your natural handrails: walk along a spur and you keep a sense of direction.
• Nested rings with a spot height or triangulation pillar are summits. Rings with a small tick inside are hollows — the flat, wet, disorientating places.

Do this practice at home: pick a hill you know, cover the names, and try to describe its profile from the contours alone. Then walk it and check yourself. That single exercise teaches more than any book.

Rights of way, access land and where you may actually walk

Legal lines on the map are as important as physical ones. Public rights of way are shown as dashed lines: a plain dashed line is a footpath, a dashed line with small crosses is a bridleway open to walkers, horses and cyclists, and dashes with plus signs and dots mark byways. These are highways in law, whatever the farmer's gate suggests.

Much upland in England and Wales is also open access land, shaded in a pale wash on the map and marked with a boundary symbol. This gives you the right to roam on foot away from paths — a freedom worth understanding, because it comes with limits. Access land may be closed for a few days a year, commonly for grouse shooting or lambing, and notices at access points or on the relevant authority's website will tell you. Access land does not include cultivated fields, and it rarely includes the land around a dwelling.

Check the legend every time you buy a new sheet. Symbol conventions are stable but not identical between scales, and a footpath in one county may be a bridleway in the next.

Grid references, scale and the numbers you need

Every map is divided by blue grid lines. Eastings run up the sides, northings run across. A six-figure reference is read along the corridor and up the stairs: eastings first, then northings, each to the nearest tenth of a square. A six-figure reference places you within 100 metres, which is plenty for a summit cairn or a road-end parking spot.

Scale matters for time, not just distance. At 1:25,000, four centimetres on the map is a kilometre on the ground. Moorland walking is slow — allow roughly three kilometres an hour on rough, pathless ground, and add a minute for every ten metres of ascent. A route that looks like a gentle afternoon stroll across two grid squares can easily become a six-hour pull through heather and peat hags.

Reading the awkward bits: bogs, crags and fading paths

Moorland maps hint at the difficulties even when the path line stops. Brown speckled areas suggest rough pasture or marsh. Short blue dashes mean streams; where several gather, expect wet ground on the flatter contours above them. Groughs — the eroded peat channels that can swallow a leg — show as crowded little wiggles on the flatter tops.

When the path fades altogether, as it will above 500 metres, navigation becomes a matter of feature-hopping. Aim for obvious things: a wall corner, a stream junction, a plantation edge, a large cairn. Take a bearing and walk it, counting your paces to confirm you have gone the distance. Above all, decide your turning point before you leave the car. Turning back at a fixed time or feature is a habit that has saved more walkers than any piece of kit.

Pack the map, a compass, a pencil and a clear plastic case. Tell someone your route and your return time. Then enjoy the moor properly, knowing exactly where you are — even when you can only see thirty yards.