Woodland That Kept Its Secrets

Walk a beech wood in late February, when the bracken has collapsed and the light comes low through bare trunks, and the chances are you will find concrete where concrete has no business being. A grey slab half-swallowed by leaf mould. A stub of wall with moss on one side and a slot cut through it. Britain's woods are full of wartime leftovers, largely because woodland was the cheapest land available when the country needed somewhere to put a pillbox, a blast shelter or a training trench.

Some of it was requisitioned in a hurry and never quite handed back. Some was planted over afterwards, the trees growing up around structures that nobody could be bothered to demolish. Either way, a little local knowledge turns an ordinary Sunday walk into something much more interesting.

Pillboxes: The Commonest Relic

If you find one wartime structure in a wood, it will almost certainly be a pillbox. Thousands were built in 1940 and 1941 along the stop lines designed to slow an invasion, and their thick walls have outlasted almost everything else. Look for them near the things an army would want to defend: canal towpaths, railway cuttings, bridges, crossroads, the edges of old fields that are now deep inside the trees.

Most are hexagonal or octagonal, with walls up to about a metre thick, and a row of embrasures or a single loophole facing the direction of expected attack. The commonest patterns are the hexagonal and octagonal infantry types; the larger, squarer ones were built for anti-tank guns. In woods you will often find them ringed by an earth bank, which was heaped up for camouflage and has since become a home for ferns, wood anemone and the occasional slow worm.

• Look down as well as up. Spigot mortar pedestals — a squat concrete pillar with a steel pin — sit in undergrowth and are easy to trip over.
• Anti-tank cubes and cylinders often line a former road or field boundary that is now a woodland ride.
• Never climb on the roof or drop into the interior without a torch. Floors are often missing or rotten, and there may be standing water and rusted barbed wire.

Many pillboxes are protected as scheduled monuments. Photograph them, sketch them, but leave them exactly as you found them — and never dig.

Airfields Returned to the Trees

The second world war left Britain with hundreds of airfields, and a good number are now conifer plantation or scrub. The giveaway is geometry. Nature rarely draws a straight line a mile long, so if the trees suddenly stop and you are standing on a cracked concrete strip with birch saplings in the joints, you are on a former runway.

Look for the perimeter track curving away through the undergrowth, and for the low brick plinths of dispersal pens where aircraft were parked under camouflage netting. Blast shelters are often little more than earth mounds with a concrete lip. Control towers and crew huts were sometimes taken over as farm buildings and are still in use, quietly disguised by a new roof and a coat of paint.

Training Grounds and Home Guard Traces

Not everything in the woods was built to fight. A great deal was built to practise fighting, which makes the remains harder to read. Practice trenches from the First World War still survive in some woodland, dug by recruits who never went overseas. In others you will find slit trenches, weapon pits and mortar positions scattered across a slope in a pattern that looks like random digging.

Home Guard posts are humbler still: a dugout with a corrugated roof, a spigot mortar emplacement behind a hedge, a concrete base for a hut that has long since gone. Keen eyes find .303 cartridge cases, shards of mess tin and the occasional boot stud after rain. Take photographs, not souvenirs; collecting artefacts from a protected site is an offence, and metal detecting needs the landowner's permission.

Quiet Memorials Among the Trees

Some of the most affecting places are not structures at all. Aircraft came down in woodland on training flights and in bad weather, and small memorials mark many of those sites: a slate plaque on a post, a cairn of stones gathered from the clearing, a wooden cross repainted by someone local every few years. You will also find benches, plaques on mature trees and simple stones dedicated to units that trained in the area before D-Day.

Treat them as you would a churchyard. Read the inscription, stand a moment, and leave the flowers, poppies and tokens exactly where they are. Tidying up is not a kindness here; the arrangement is the memorial.

Walking Them Well

A little preparation makes these sites far easier to find and safer to enjoy.

• Use a large-scale map, ideally 1:25,000, and look for dead-straight boundaries, oddly shaped plantations and tracks that lead nowhere.
• Go in winter or early spring. Undergrowth hides almost everything by June, and you avoid disturbing nesting birds and bat roosts — pillboxes are favourite bat hibernation sites.
• Wear boots, carry a torch and gloves, and tell someone where you are going if you are exploring alone.
• Park considerately, close gates, keep dogs under control and stick to public rights of way unless you have permission.

These woods are not museums. They are working landscapes with a memory, and the stories they hold belong to the parishes around them — to the families who watched the bombers leave, and to the men who never came home. Walking them quietly, with a map in one hand and a bit of patience, is the best way to keep those stories alive.