The Ditch on the Welsh Side

What Offa's Dyke is

Offa's Dyke is a linear earthwork running roughly eighty miles along the border between England and Wales, built in the late eighth century on the orders of Offa, king of Mercia. It is not a wall in the Roman sense and it never had a stone facing. It is a bank with a ditch, and the ditch is always on the western, Welsh side.

That single fact is the whole design. The bank is the defensive element, and its steep side faces the ditch, which means the steep side faces west. If you are walking the Dyke and you find yourself looking at a gentle slope with a hollow beyond it and the high ground behind your shoulder, you are standing on the wrong side — you are on the Welsh side, in the ditch, which is where an attacker would have been.

Stage one: reading the profile

At the published coordinate you are on the Dyke where it crosses a ridge in the Clun Forest. Walk twenty paces along the earthwork in either direction until you can see a clear cross-section.

The stage one marker is a small tag on the fence post at the point where the Dyke meets the modern field boundary. It asks you to record the height of the bank and the depth of the ditch in metres, measured against your own body, and then to give the ratio as a whole number.

That ratio is your first stage value. It is usually three or four in this section.

Stage two: the gap

Follow the Dyke south-west for about six hundred metres. Where a stream crosses the line, the earthwork stops and starts again on the far side. This is a genuine gap, not erosion: the Dyke was dug in sections between natural obstacles, and streams, steep slopes and marshy ground were used instead of digging.

The stage two container is a micro attached to the underside of the footbridge that carries the path over the stream. It gives the offset for the final.

Stage three: the final

The final is under the root ball of a windblown oak about two hundred metres further on, on the uphill side of the ditch — which is to say on the English side, above the bank, where the defenders would have stood.

This is the point of the cache. Everyone who does not read the profile properly ends up searching the ditch side, which is downslope, wet, and has no oak in it. The container is a small clip-lock wedged into the peat and soil still held by the roots.

Terrain and footing

• The Dyke in the Clun Forest is high, exposed and frequently muddy. The ditch holds water from October to April.
• The bank is steep enough to be awkward when wet and there is no path along the crest. Walk beside it, not on it.
• The earthwork is a scheduled ancient monument for its whole length. Do not dig into it, do not metal detect on it, and do not remove stones from it.
• Livestock graze the ridge. Sheep will follow you for some distance hoping for food; do not encourage them.

After the find

The Kerry Ridgeway, a few miles north, is a prehistoric route with a view that takes in both countries on a clear day. Knighton, south of here, has an Offa's Dyke Centre that is worth an hour if you want the archaeology properly explained.