Exploring the wilder fringes of the Astley Ainslie Hospital estate, we stumbled upon an enticing little path sheltered by woodland and flanked by knee-high grass, it was narrow but clearly well-trodden. Curiosity drove us forward. After five minutes of walking, however, a foul odour filled our nostrils. The source lay right beneath our feet: a sluggish burn trickling from a grating, brewed to a stink by the warm weather.

The burn extended ahead, heading further west, the land narrowing around it. This is one of the few places where it still breaks the surface, one of the rare moments in its largely underground journey where it can actually be seen - and smelt.

It took me back several decades, to a long evening bent over a keyboard, tiredness and frustration almost overwhelming me. This was the final night before my primary school project was due. Its subject was that very waterway, the Jordan Burn, a waterway whose precise source nobody has satisfactorily settled, largely hidden from view as it made its way through Morningside and other leafy parts of the city.

Converted mostly to pipes and hidden culverts, the burn made itself known chiefly through absence; most notably the gap where a tenement block should have stood opposite the old Post Office. Building over running water was never wise, and the burn had been quietly undermining Morningside for centuries. Alarmed residents discovered water murmuring beneath their floorboards; frontages subsided and faced demolition; building projects stalled. All because of a stream most people never knew was there.

These details found their way into my project, alongside photographs I’d taken at points where the burn was publicly visible, including the grounds of Woodburn House, then used by the NHS. The project drew on the work of renowned local historian Charles Smith and a grainy Super 8 film about the burn made by his brother, Bill.

It’s not the contents of the project I remember, but what it left behind: a lifelong appetite for tangible history, the kind discovered by clambering over a wall or following a hunch. The Jordan Burn offered plenty on that score. Likely rising on the southern slopes of Craighouse Hill, it marked Edinburgh’s official southern boundary until 1856. Famous men had crossed its banks; there is even evidence the Romans bridged it. Yet here it was, reduced to a culvert, a rumor beneath the floorboards, a gap in the tenements. Buried during the late-nineteenth-century expansion of south Edinburgh, the burn never truly disappeared; it was simply swallowed by the suburb growing over it.*

The memories of that final evening have stayed with me. I was using an elderly BBC Micro my dad had salvaged from work. I seem to recall that FX6 was the print command. That evening bled into early morning as getting the document to print proved exasperatingly difficult. When text finally emerged onto the green-tinged, sprocket-holed paper, I spotted a multitude of errors. “Well, if you leave things to the last minute…”

I was on the verge of giving up. Another hour of painstaking corrections; then, after a stress-inducing pause, another whir-and-screech of the dot-matrix printer. Next came the assembly: photographs and photocopied maps combined with text the old-fashioned way. With the Pritt Stick running low, nothing would properly adhere. Would Sellotape do? Blu-Tack? The confidence I’d felt the day before now seemed hopelessly naïve. I should have been at this stage twenty-four hours earlier. How many times have I said that since?

The walk along the burn ended in similar frustration. In that stretch it runs through a narrow corridor, squeezed between garden walls and the South Suburban railway line. This is the same stream that, further along, becomes the Pow Burn, joins the Braid Burn at Peffermill, turns into the Figgate Burn at Duddingston, and finally empties into the Firth of Forth at Portobello; a ten-mile journey, much of it invisible or hard to reach.

Here, at Astley Aislie, the bank path grew increasingly uneven and narrow before petering out. Alone, I might have tried to force a way through the thicket, but it looked hopeless. It was time to admit defeat. Once again, the Jordan Burn had got the better of me.

*This account draws on Historic South Edinburgh by Charles Smith, published by Birlinn.