The frozen path booms dully under my boots. On my right a burn runs the colour of Bisto. Oak leaves corkscrew limply down.

In Whistle Stop Walks, I take the train to a station, walk on, and pick up the train home somewhere down the line. As close as I can get to a zero carbon day out.

I am in a little green valley just north of Haltwhistle in Northumberland. On a craggy summit like a crusty loaf is Hadrian’s Wall. I fill my notebook with hopeless artists’ impressions. But even their amateurish inexactitude cannot obscure this fact: the Romans couldn’t lose.

Hadrian’s Wall Path, one of Britain’s premier league long distance trails, shadows the wall, or its original line, for 84 miles, from Wallsend to Bowness. I’m on the grandest central section, where the wall plunges and rears through a wild and ravishing landscape.

At one point I follow a minor road to the wall’s north side. By rights you should come here first and behold the frowning face of the Roman Empire. After all, you don’t see a great cathedral for the first time from the inside.

One of the most spectacular surviving sections is at Walltown Crags, where the views stretch as far as Scotland. Strolling down to Brampton station, I salute the shades of Legio II Augusta, who built this wonder of the world. Then the train back to Newcastle.

by GARETH HUW DAVIES