Guide
Reading the Ground
How to tell a motte from a spoil heap, an enclosure wall from a medieval hedge, and a lynchet from a natural terrace, without any equipment at all.
Most of what is worth noticing in Powys has no sign on it. The skill is not knowing facts; it is knowing which lumps in a field are worth a second look.
Mounds
A motte is a flat-topped cone, usually between four and ten metres high, almost always with a ditch round the base and often with a low rectangular platform attached — the bailey. It will be near a stream crossing or on the edge of a valley. Powys has hundreds.
A round barrow is Bronze Age, lower and more domed, usually on a ridge or skyline rather than in a valley, and often in a group.
A spoil heap is loose, steep-sided, sterile, and has different vegetation from the ground round it. Near it there will be a hollow it came out of.
A tump with a very flat top and a suspiciously regular shape may be a windmill mound, a prospect mound in a park, or a rick stand.
Banks and ditches
Which side the ditch is on tells you the purpose. A defensive work has the ditch on the side it expects trouble from. A boundary has the ditch on the outside of whoever built it, because the spoil goes on your own land.
Offa's Dyke has its ditch on the west. That is the single most quoted fact about it and it is the reason most people read it as facing Wales.
A leat is a channel running along a contour, remarkably level over long distances, taking water to a mill wheel or a mine. If you find a horizontal ditch that does not drain anything, follow it.
Fields
Ridge and furrow is a corrugation of the surface, ridges a few metres apart, produced by ploughing in one direction over centuries. Where it survives in Powys it is on valley floors that were arable and have been pasture ever since.
Lynchets are terraces on a slope, formed as soil moved downhill against a boundary during ploughing. They look like natural steps and are not.
Hedgerow dating is a rough tool worth knowing. Count woody species in a thirty-yard stretch, take the average of several stretches, and each species is very approximately a century. It is unreliable in detail and useful in comparison: a hedge with seven species is older than one nearby with two, whatever the absolute dates.
Wall shape is the fastest indicator in Powys. Straight walls running across open hill are parliamentary enclosure, late eighteenth or early nineteenth century. Irregular curving boundaries with big hedgerow trees are older, often much older.
The abandoned
House platforms are level rectangular cuts into a slope, usually with a slight bank round three sides, often with nettles growing on them because of the enriched soil. A run of them in the ffridd is a deserted settlement.
Longhouse foundations are long narrow rectangles, typically four or five metres by fifteen or more, with a cross-passage visible as a gap in the side walls.
Trees tell you. Sycamore and ash in a group on open hill usually means a dwelling. Nettles and docks mean nitrogen, which means dung, which means people or stock. A lone rowan by a ruin was often planted deliberately.
Ground under grass
Two conditions reveal earthworks that are invisible the rest of the time.
Low sun, in early morning or late afternoon in winter, throws shadows across slight bumps and can make a whole field system appear that you have walked over a hundred times.
Light snow, or a hard frost thawing unevenly, does the same thing from the other direction.
Then check
Nothing above proves anything. Everything worth a second look should be checked against Coflein, which is free, and the local Historic Environment Record through Archwilio. If a site is not recorded, and you are confident, the HER will want to know.
Do not dig. Do not detect. On a scheduled monument both are criminal offences, and on anything else you will destroy the evidence for the thing you noticed.