“Looks like we brought the weather with us from California,” the elderly tourist says, pulling on a hat and strolling past me. He disappears up a grass slope, beneath a brilliant, blue sky, his wife beside him.

It’s the first of several American accents I hear that morning. Perhaps they’ve come to see what a real border fence looks like.

Because that’s precisely what’s drawn them, and me, to this remote and spectacular part of northern England: An imposing, defensive barrier meant to keep the bad guys out and the good guys safe.

At least, that’s how the ancient Romans would have seen it.

Hadrian’s Wall – named after the emperor who commissioned it – was begun in the second century, in the year 122. Soldiers toiled for a decade or so, piling stone upon stone until it stretched from coast to coast, across the very top of what’s now northern England – a distance of 118km.

It stood up to 4.6m high with walls 3m wide. It bristled with towers, forts and watch posts, called milecastles, and gave commanding views of the surrounding countryside.

Trendy designers today like to talk of statement walls. This was, indeed, a statement wall. It was where civilisation ended.

The wall let the Romans control who and what came into the empire. And it kept the peace. Beyond it were war-mongering communities in what is, today, Scotland, itching to ravage the settlements of refined Roman Britain and bring down fire on the hated invaders.

England

The wall used to run from coast to coast, a distance of 118km.

Hadrian’s Wall kept them out.

Almost 2,000 years on, long sections of Hadrian’s Wall still stand, remarkably well-preserved. The thick stone line snakes for miles across rugged uplands, and down into wooded valleys.

Unesco named it a World Heritage Site in 1987 for its “extraordinarily high cultural value”.

My family and I start at the ruins of Birdoswald Fort, said by English Heritage, a charity that looks after historic sites, to have the most impressive remaining defences of all the original 16 forts. We then follow the wall, in blazing sunshine, as it undulates eastward.

England

The remains of a Roman building within Birdoswald Fort. There were 16 forts in total along Hadrians Wall when it was built.

But they soon tire of this huge slab of history, preferring the lure of a shady river bank and a packed lunch.

I go on alone, past the impressive remains of abutments that once supported a triple bridge across the River Irthing. The wall’s thick spine ascends a hill ahead of me.

You are not meant to climb up on it, but I have an urge to connect. I run my hand against the sun-warmed stones; some a whitish-gray, others blackened by an eternity of wild, northern winters. I marvel that the last person to touch them, before me, was quite possibly the man who laid them, back when Hadrian’s Wall marked the extreme northern edge of the Roman empire’s vast reach.

Sitting on the edge of an escarpment, among the ruins of Harrow’s Scar milecastle, a ruddy-faced walker is taking a breather. Bill Vincent is halfway through a six-day trek along the wall’s entire length, coast to coast, “to mark the start of my 60th year”.

I ask him whether he thinks about the history as he walks – the garrisons, shivering behind the ramparts; the tattooed tribal warriors, staring resentfully at this massive stone affront.

“Yes, you can’t help but do that,” he says, “but, to be honest, I think more about my feet.” – AP/Jerry Harmer