How many times can you photograph a wall?

Can you snap it in a thoughtful mood, a playful mood, a coquettish mood, perhaps when it's not looking?

Is it possible to capture the hues in its stone, the cracks, the fissures, the signs of age, of wear and tear?

After all, a wall is just a wall isn't it? A mixture of stones and rubble, perhaps mortar, dirt, the accumulated detritus of the years. It stands or it falls depending on the skill of its builder and the strength of its foundation. But it's still a wall, doing a wall's job – keeping something or someone from gaining access to something or someone.

Unless it's Hadrian's Wall and unless the person taking the photographs is Derry Brabbs, known for his pictorial collaborations with Alfred Wainwright and James Herriot.

If the truth be told, only a fraction of the Roman emperor's massive monument remains intact; much of the stone was pilfered over the centuries to be used in building castle, churches and farms. This was a huge fortification, a barrier between the far-flung outpost of the greatest empire the world has ever seen, and the savage Picts and Scots to the north. It may have suffered in the ensuing centuries, but what's left of this World Heritage Site is sufficient to inspire.

And that's why Brabbs has spent months trekking back and forth to photograph the legacy of countless legionnaires who lived and died along its 73 miles between the Solway and Tyne.

"It was a spine-tingling and somewhat humbling experience to stand alone on one of the wall's highest vantage points, touching blocks of stones that were originally slotted into place by second-century soldiers," he says.

Many of those blocks may have vanished, but there's enough of the wall left to show just how great an engineering feat this was. It was precision-made by man – by men – long before modern machinery and high-tech surveying equipment. It has stood the test of time, and Brabbs has done it justice, capturing its many moods in many weathers. But he would have had little to photograph had it not been for the far-sighted John Clayton, town clerk of Newcastle and a keen antiquarian who almost single-handedly helped to preserve what remains of the wall.

"Clayton was appalled at the way in which landowners showed scant regard for the wall's historical value by persistently plundering its stone," says Brabbs, in tribute.

"So, from 1834 onwards, he began buying farms and properties whenever they came up for sale and his labourers were then tasked with the job of clearing and rebuilding long sections of the wall on his newly acquired property.

"That wonderful act of altruism has ensured that some of northern England's most dramatic countryside is still enriched by the physical presence of Hadrian's Wall, rather then being reduced to a few shards of pottery buried under the earth."

Hadrian's Wall, by Derry Brabbs, is published by Frances Lincoln, priced £14.99. To order a copy from the Yorkshire Post Bookshop, call free on 0800 0153232 or go online at www.yorkshirepostbookshop.co.uk. Postage and packing is £2.75.