I’m not sure exactly when the question enters my mind, possibly at Junction 10 of the M8 motorway or maybe opposite the Shandwick Centre in Easterhouse while watching people queuing at the bus stops. It’s this – when Harry Bell set out to discover the old, now-invisible tracks criss-crossing Glasgow, did he ever envisage the extent to which roads would dominate the city? Or how in Easterhouse, an area of low car ownership, the city becomes ever more inaccessible to its people? Passing the site of the Stirlingfauld Flats recently I was surprised to see the huge mounds of rubble gone, used in the making of new roads. It’s like the old saw – the best thing to come out of Glasgow is the M8.

I’m barely out the door on this bright spring morning before I hit the construction works for the M74 Completion. Rather than address the chronic pot hole problem of the existing roads, the Scottish Government is hellbent on driving an unwanted section of motorway through the heart of the southside. The old road to the city centre, the A77, is snagged, reduced to single lanes in both directions. Off Eglinton Street, massive concrete pillars are being erected for an elevated highway linking to the M8 and the Kingston Bridge. Opposed by many, the road will inevitably eat its surroundings, isolating the extant buildings and the people who live and work in them. Still, the concept of completion is uppermost in my own mind as I embark on the final few trips to Harry Bell’s sites to record what’s there. That’s assuming I ever arrive.

My trip today takes me north east in search of a place that intrigued Harry Bell more than any other site – possibly because it doesn’t exist. In his book, Glasgow’s Secret Geometry, he includes a rough diagram revealing the sites and alignments deemed by him as proof of a network, created over hundreds of years. On the upper right hand side of this map I find a line punctuated with an arrow. It’s marked The Straight Road with no Path.

On the GNAS website he states –

When I first read this paragraph in 2001, the year Harry Bell died, I was captivated, both by his enthusiasm and the quest he set himself. I’ve long believed that the most familiar places hold mysteries, but unlike Harry Bell, I have no passion for archaeology or local history. Rather, my own interest in the past stems from the tricks played by the subconscious; the connections conferred on our surroundings.

Filtered through memory, place prompts sensation, often in irrational ways. Growing up in the squalor of 1960s Kinning Park, as long summer evenings gave way to the night, the sight of a warm glow of a lamp from a curtained tenement window induced in me a profound yearning for refuge while struggling in my plural perception with some unspeakable evil on the other side of that curtain. To this day, whenever I see a lamplit window, I become a tourist again, navigating time, not distance.

A born southsider, I’m not intimately acquainted with the east end of the city. Seems the main reason for exiting at Junction 10 these days is Glasgow Fort, a generic silver-walled retail opportunity boasting the usual suspects, classier than Parkhead Forge but no match for Silverburn, with its branches of Kurt Geiger and Wagamama.

Rounding the corner at Auchinlea Road, I catch my first glimpse of Provan Hall, cited by Harry Bell, whose Gazeteer (sic) of Sites informs me it’s –

A hand-painted sign announces Fun Day, but it’s early doors and I’m among the first visitors. A stall promoting the Forestry Commission displays an impressive set of stuffed wild animals and birds while opposite, an inflated attraction, Fun and Games, invites punters to kick a football through deceptive holes. Other stalls include face painting, DVDs and games for sale and refreshments.

The Hall itself is more compact than I had imagined, described by the National Trust as “probably the most perfect pre-reformation mansion house in Scotland“. Before long I’m approached by a talkative volunteer who offers me a leaflet for the Friends of Provan Hall. He informs me that the Hall has recently secured a £4.5m donation, £1.5m of which will provided by Marks and Spencer, an act of largesse not unrelated to their application for a 16,000 sq. metre development at the Fort, a plan recently approved by the city’s planning department and conditional on a £10m ‘developer contribution’ to improve the town centre, revenue-raising the name of the game. The leaflet I’m handed admits as much, stating how ‘Local authorities are unable themselves to do and fund everything that is needed in most parks’. Isn’t that what we pay Council Tax for?

I’m introduced to Stevie Allen, keeper of the Hall and its sole employee. Stevie tells me that for the last 22 years he’s given tours and generally maintained the property. He’s also keen to tell me that The Ghost Club, the UK’s oldest paranormal group has conducted several vigils at Provan Hall and discovered a significant level of activity. A self-taught expert of the Hall’s history, Stevie recounts how the murder of a woman and child took place here. A later trawl of the Ghost Club website reveals how in recent times a young woman hung herself in the grounds.

Feeling slightly spooked, I look over the house – not grand but typically Scottish: solid walls, vaulted ceilings and crow step gables. To my untrained eye there’s little by way of apparitions today, but plenty of visitors, locals mainly. In the modest, well-kept gardens, seeing my camera, a young boy approaches me. ‘How much d’you charge for a photie?’ he asks, unaware he’s just offered the perfect summation of the times we live in.

Taking a detour, I pause at Gartloch Hospital, a location used during the shoot of my second feature film, Solid Air. At the time I was informed that the ex-psychiatric hospital, closed in 1996, was due for redevelopment into luxury properties. Today the imposing main building, a Victorian Gothic confection, still stands vacant, surrounded by what the developers, New City Vision, describe as ‘eight hamlets’ designed in a quasi-feudal arrangement comprising sleek steel and glass-fronted detached units, smaller detached and semi-detached houses, a forelock-tugging nod to the traditional, with misbegotten columned entrances, cottagey windows and pitched roofs, alongside modern-styled terraced townhouses and flats.

As communities go, I’m not sure the Village succeeds. Aesthetics apart, it’s ironic that regardless of how much you pay to live here the lack of amenities is universal – no school within walking distance, no corner shop, no pub. Without a car, you’re completely gubbed unless you walk the mile or so to Easterhouse. Unsurprisingly the developer’s website omits Gartloch’s past as a repository for the insane, instead rebranding the asylum as some kind of rural idyll, evidenced by their nightmarish CGI animation of the site and the plots for sale.

Not wishing to dwell in or on Gartloch Village, my next stop is another of Harry Bell’s sites. Woodend Loch, a Mesolithic site north of Drumpellier Country Park off the Townhead Road, has been designated a SSSI. The reason isn’t obvious. Harry Bell cites the recovery of worked flint tools on the north shore but as I position my camera all I can see is barbed wire fencing and an electrical sub station. Even in today’s sunshine the place exudes bleakness, in contrast to the neighbouring park where today daytripping hordes make the most of the weather.

At the town of Twechar, situated off the B8023, I’m searching for Barhill Roman Fort, marked on Harry Bell’s diagram as the northern end of an alignment passing through Carmyle Fords and terminating at Dumdruff Hill. I soon find a helpful signpost next to a tiny church, the Twechar Nazarene Church, a modest construction and fitting testament to the miners who built it.

Despite what the signpost tells me, the path to Barhill proves longer than a quarter mile (it’s more like half a mile) but ultimately it’s rewarding. After an unscheduled tour of a sinister-looking domed reservoir owned by Scottish Water and almost landing in the world’s biggest dunghill, I pick up the trail.

The walk is well worth the effort – the views over the Kelvin Valley and the Campsies are stunning. Set on a section of the Antonine Wall, all that remains of the fort are foundations, but as strategic positions go, they don’t come any better than this. According to the excellent Roman Britain website a smaller, earlier fort was believed to have been constructed around AD80 during Agricola’s campaigns.

It’s pointless to speculate what the legions who built Barhill made of their surroundings and in what ways the landscape differed from what’s here today. I still find it curious that no significant Roman sites have been discovered south of the Clyde. It’s certainly a place of ancient foundation, the criterion applied by Harry Bell when he first set out to trace what he would call prehistoric communication lines. Scanning the horizon, I make out Dumgoyne to the north west and, far to the west, I light on a tree-topped mound – Castle Hill – another Roman site cited by Harry Bell.

With the weather holding up, next I head for Kilsyth, taking the Tak Ma Doon Road through the Kilsyth Hills towards Carron Bridge, my final site today. Pausing to drink the dregs of my flask, I’m at the car park, a favoured dogging spot popular also with the usual stoners and boy racers. Seems the longer I’ve been on this journey, the more I’ve found several of Harry’s sites – usually viewpoints in outlying areas and reachable only by car – have reputations as venues of misadventure. Was he aware of this, I wonder?

Checking my OS map against Harry’s diagram, I’m convinced the distant grey-blue lump before me is Tinto Hill, the end of another alignment, one stretching from as far as Duncolm. As I puzzle over sightlines, I overhear a lone but loud taxi driver. Fat and bespectacled, he slugs a Diet Coke while barking on his radio the worst string of expletives I’ve heard in a long time, a language so beyond casual swearing it warrants documenting as an artform in its own right.

By the time I reach Carron Bridge, it’s early evening and the sun’s starting to dip, the shadows spreading slowly, consuming the light, blood-viscous. I’m puzzled why Harry Bell fails to mention the Tak Ma Doon Road (he only mentions Campsie Fells) as a possible route taken by old Saint Mungo and Fergus’ untamed oxen-powered funeral cart. They travelled from Carnock, closer to Alloa and Dunfermline than it is to Stirling as most historical records have it, a far greater distance from Glasgow than I anticipated. The maps I find don’t go as far back as the 6th century, so whether the Tak Ma Doon Road existed then, I can’t be sure. It’s certainly a direct route from Stirling to Glasgow, if not exactly a straight road.

Did Mungo take this route, I wonder? If he did, he’d have to cross the Carron. Trudging along the north bank of the river with my camera and tripod, I feel the place certainly has a resonance. And as much as I hate to contradict Harry Bell, today there’s no such thing as Carron Fords, vanished when the nearby reservoir was built during the nineteenth century. Standing at the river’s edge, however, it’s entirely possible to cross and hardly get your feet wet. I take my shots. It’s a perfect late spring evening – the sky almost cloudless, the light amazing. If I were to stay here long enough I’d have the stars all to myself. That, or the lamp-lit glow of the Carron Bridge Hotel to comfort me.

Meditating on this, for the first time in months I feel at peace. Then, out of nowhere, my thoughts stray to my late mother, who in 2003 died in the hospital I was born in. She was not a religious woman. Her funeral was conducted by Joe Hughes, a Humanist Society celebrant whom, coincidentally, oversaw proceedings at Harry Bell’s funeral two years before. Taking my final shots of sunlight playing on the water, I muse, thinking, just as Mungo did all those centuries ago, that I will carry the dead along this road all the way back to Glasgow, not on a pair of untamed oxen, but in an untamed mind.