Flowing under the roadways of Morningside, it's very much hidden from view, but that hasn't stopped the ancient Jordan Burn from having an impact on the urban landscape.
Above the Sainsbury's Local near the foot of Morningside Road, the broken remains of a 19th century tenement can still be seen, with the building adjacent being propped up by giant wooden beams.
READ MORE - The forgotten Edinburgh tenement collapse you can still see evidence of today
It's a curious sight that only the keenest of observers will notice, yet it stands as testament to the unrelenting flow of the ancient Jordan Burn.
Originally called the Pow Burn, it was later renamed to reflect other Biblical names in the district, such as "Little Egypt", "Nile Grove" and "Canaan Lane".
The subterranean stream has appeared on maps going back to the 1750s, but is now mostly hidden from view. Ignore the existence of the Jordan Burn at your peril, however.
In the late 19th century, tenements were built over part of the Jordan Burn as the population of the Morningside district soared.
What the Victorian builders failed to take into consideration, however, was the effect that the burn would have on the stability of some of the new buildings.
Within decades, the Jordan Burn would cause the entire building to cave in. Doors jamming and cracks appearing in the walls of the tenement flats at 358-364 Morningside Road would have been the first tell-tale signs of subsidence.
Photos show that the tenement survived until the post-war era. To prevent further issues, the adjacent tenement at 368 Morningside Road was shored up by huge 20-foot-long wooden supports.
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In the past decade, much of the ground floor of the broken tenement was redeveloped for the construction of a Sainsbury's Local, but, for the time being, the remains of two old window recesses can still be seen above the new supermarket.
The site is currently the subject of a planning proposal which would see the old "broken tooth" extracted and a new six-storey apartment building erected.
Last year, Edinburgh Live reported on how Melville Street-based property developers 83S Ltd, owned by Steven and Victoria Jones, is proposing to build a six-storey building, with a basement retail unit and a steel balustrade on the exterior of the top storey.
Let's just hope the builders take the flow of the Jordan Burn into account this time around.
Where can we see the Jordan Burn?
Now enclosed in a series of enclosed pipes and culverts, the Jordan Burn was visible above ground until at least the 1880s when the Morningside area as we know it today began to develop.
Its historical importance stems from the fact that, until 1856, it marked the boundary of both the city and the county (Edinburghshire).
The source of the burn was traced in the 1970s by devoted Morningside historian Charles Smith, who traced it to Myreside near the slopes of Easter Craiglockhart Hill.
The Jordan Burn's path is said to twist and turn from Myreside towards Maxwell Street before crossing the roadway beneath Morningside Road. From here it heads eastwards along the back gardens of the appropriately-named Jordan Lane.
The burn surfaces briefly in the grounds of the Astley Ainslie Hospital on its way to Blackford and Mayfield, where it reverts back to its original name, the Pow Burn.
It eventually merges with the Braid Burn at Peffermill and enters the Firth of Forth as the Figgate Burn at Portobello. From source to sea, the distance is approximately ten miles.
