What We Know

Nigel TurnballThis website was setup to retain and continue all the good work and valuable information collated by the late Nigel Turnbull.
All first-person references within the text are referring to Nigel.


The Torwood Blue Pool is a round brick lined pool which in a cleared strip of Tor Wood to the south west of Torwood, north of Denny and Larbert.

Torwood Blue Pool

The questions:

  • What was the function and purpose of the blue pool ?
  • When was it built ?
  • Who built it ?
  • When did it cease to have a purpose ?
  • Where does the water come from and why does the level change ?
  • Did you ever swim in it ?

What we know so far 

Torwood Blue Pool near Dunipace

Land Utilisation Map

I first came across the blue pool in 1961 when I was ten years old. I lived in nearby Dunipace. The pool looked exactly the same then as it does now but I don’t remember there being any trees around it.
My uncle, also a local, remembers it from his youth (late 1930’s) and described it as looking just the same.

A lifetime later I had forgotten the exact location of the blue pool but rediscovered it in 2007. Most people I speak to refer to it as the Blue Pool. The blue pool had a remarkably vivid blue colour and was crystal clear. It was like looking through a blue diamond and you could see the bottom quite clearly — according to my 45 year old memory.

The blue colour, it seems, is not that big a mystery. I wrongly thought that water got its blue colour from reflecting the blue sky but it seems that clear deep water refracts light in such a way that it produces its own blue colour.

Torwood Pool looking blue

Torwood Pool looking blue

If the above is true I would expect to see the same colour in our reservoirs but I have never seen that blue colour anywhere in Scotland other than the Torwood Blue Pool. Are there any water and light-refraction experts out there ?

Could the blue colour have anything to do with dissolved chemicals or minerals ? Nobody who was exposed to the water has reported a desire to put the letter ‘S’ on a T-shirt and leap tall buildings.

If the pool was being fed by an external source of water, I would rather expect the level to be constant but this is not the case.
Is it simply being topped up by rainwater and evaporating during dry spells? Would this make it a ‘stagnant pond’?
If so why is the water so clear and odourless? is the algae and plant life keeping the water clean?

Torwood Blue Pool looking West-ish

Looking West-ish

Heather Livingston from Ontario, Canada.
There were no trees near the pool in 1983. The only trees were across from Torwood castle.
For some reason we always stayed on the side looking towards Torwood castle — smoother land? I remember getting out of the pool the same place as the dogs do — not sure why.
It was always an open area. Only walking on the foot path [right of way path to Denovan, heading south] near the castle were there trees — then it opened up to open fields.
I do remember the water being clear too and seeing the bottom in 1983. I just remember the debris of trees at the bottom. I never actually swam to the bottom.

Torwood Blue Pool looking North-ish

Looking North-ish

Caroline Kerr from Aberdeen, Scotland.
I grew up in Dunipace and visited the blue pool quite often while out walking. I always wondered what it was for. My father said it might be an old airshaft for a mine. I have written in my photo album that the pool is very blue.


For further reading, please start at the posts page.


184 thoughts on “What We Know

  1. Joe Malone

    Found an article 1864 while searching through “Findmypast” website might be of interest to you in relation to Torwood blue pool drop me an email and I will send you PDF file.

  2. Gerald McNichols Tetreault

    I am chief conservator for the restauration of a 350 year old building and garden in Montreal Canada. We found a similar pool in 2009 during the archeological research previous the restoration of the garden. The same architect whom worked for the owner in c.1860 of our building was from England and had built at least two important gazometer in Montreal. It would be really interesting for us to get in touch with the people whom made these discoveries in UK. Any of you could reach me at gerald.mcnichols@videotron.ca

  3. Neil

    Can anyone tell me if the Blue Pool appears to be near any buildings i.e – homes or former homes or workplaces? Also is it downhill or near and possibly connected to a reservoir or loch?

  4. Fiona McArthur

    I have loved reading all of this and found it brilliant I do hope that some one is keeping up Nigels long work on this pool I know that he did a lot of work up by torwood and the brooch I would love to hear if the pool was ever drained and what was found please keep posting info on this site love it.

  5. alan smeaton

    Must go back to the pool again soon. Lived in Plean till 1969 and found the pool by accident in those days when I would ‘explore’ all day around the Glen Road area.
    I have lived repeatedly at both sets of cottages on the Glen road, the ‘Plean end’ ones when my father worked at Carbrook Mains farm – even remember the mine working – and the ‘forestry ones’ when my father worked at the old sawmill.
    I used to collect yellow raspberries, presumably from the gardens at Carbrook house – don’t remember any structure apart from a few stones in the mid ’60s but do vividly remember the basement entrance but never plucked up the courage to go down into it – maybe to do with getting stuck down a huge pit in the woods near the sawmill cottages. If you have any photos of Carbrook house or the old sawmill I’d love a copy to look at. My father, now in his 80’s would also be interested. I have recently asked my mother to dig out her old photos for me to scan so maybe find something there too.
    Hope you can help David & Stephanie (and anyone else!)

  6. David + Stephanie Hunter

    After a least 25 years of searching I have found and own the photos of Carbrook House and Coach House.
    Anyway back to blue pool! Whilst researching Carbrook basement I have found out that the same red unmarked brick (hand thrown) is the same as Carbrook pool and the blue pool. Anyone who has read my previous finds wil see that I beleive both pools are connected, so the question now is if the house and Carbrook pool are built of the same brick and are connected to the blue pool all on the Forresters Land the brick is the same age WHY? If this was air shafts for a coal works why would the Laid allow this to be behide his coach house? I have more questions than answer So wish we had found these photos sooner Nigel would have loved to see them. We are also waiting for the mine works maps for Torwood. WARNING Carbrook basements are not safe to go down very dangerous.

    1. admin Post author

      Interesting find and thank you for sharing. The Torwood mine works maps may reveal quite a lot and may create more questions than answer!

      What are your thoughts on posting the photos on this site? I’d be interested in seeing those. I fear though they may be creating more questions that answers too!

      1. David + Stephanie Hunter

        Hi yes we are looking forward to seeing the mine works as Dave wants to prove that his dowsing works!
        I can email you the photos we took of the basement at Carbrook but the photos I got I am not sure about the copy right law I will ask if I can do this.
        I think you are right about then mine works giving more questions than answers really looking forward to seeing them.
        Going back to the dowsing Dave met Nigal a number of times and on one occation Dave showed Nigel Dowsing he has been alround Torwood carron iron works Denny Dunipace Denevon and Plean collinary and the blue pool is a spiders web of tunnels! One of which leeds to Carbrook pool which appears to have two tunnels one leading to the blue pool the other to plean coke kilens (back road at Plean) the by product of coke is coal gas !!!!!!

        cheers Steph

  7. Martin

    Had the fleabag a walk up Torwood on 2nd June – Water level of the pool was at least 3ft from the top row of bricks…never saw it so low. Has someone been draining it?

  8. Irnbru

    Further investigation has revealed that this is NOT a colliery air shaft. It may well still be an air shaft for a mine – but it is definitely not the Quarter Colliery.

  9. Alana Bowman

    Absolutely fascinating, I have never heard of this and have asked various family members who know nothing about it either. I shall definitely be going for a nosey. would love to find out one day what it was.

  10. Dave + Stephanie Hunter

    Hi we would like to continue with the Blue Pool also, we meet Nigel a few times and took him dowsing. I am not sure who is the administer of the sight, the gentleman who has access to the Torwood Castle knew Nigel and may know? HOpe this helps

  11. Irnbru

    I have been continuing the work left by Nigel.

    I would like to contact whoever now administers this website in order to update them with my recent findings.

  12. Martin

    Was up at the Blue Pool in early January, haven’t saw the water so clear in a while, no litter either.
    Glad to see someone’s removed the infantile patter from here too

  13. Rosalyn

    We visited the Blue Pool today for the first time. It was possible to see to the bottom which was full of branches and debris. We saw the tunnel arch. There had been fires lit around the pool and bottles etc around the area. Really interesting place. Some sort of work was being done to Torwood Castle today as well.

  14. Colin Crawford

    Speaking to my dad today says it was 60 years ago he was there,the Blue pool at that time (1950ish) had a 6 foot high metal wall surround with metal beams across the top ,but no roof.As a boy he had to climb up the sides to see the water on the other side.Hope this helps.

  15. Martin

    Took the mutt a walk up Torwood on March 20, had a nosey at the Pool – I noticed some clown has thrown the metal pole/turnkey for the square drain into the Blue Pool

  16. Richard Holmes

    I went up to see the blue pool with our walking group on Saturday 03 March 2012.

    The pool had bluish clear water and sparse weed. I thought I saw two brick arches, one on the north side and the other on the south side. The site intrigued me.

    In mind of Guestbook site previous reports of submerged pipes, a nearby manhole, key etc I find it most easy to think of this site as having had some former industrial reservoir use in Victorian times or thereabouts. That is, the pool was purpose built to provide a gravity-driven head of water which with a requirement also for pure water. A pure head of water used for quenching coking ovens, or for hospital use?- both sound good to me(previous suggestions posted at this site). Pure water (with neglible dissolved minerals)would also be valuable for supplying clean water to boilers to provide power for steam engines. I presume that the low pH and low dissolved mineral content would militate against mineral scale forming in the boiler systems. Pure water generating steam power could conceivably have been used for lifting contaminated water for from mines, quarries and/or lifting solids from mines, quarries and/or for mine ventillation.

    The previous Guestbook report of concrete staunchions set into the (nearby?) country side also points to a local history of industrial-size incline-based lifting.

    My thoughts about a connection to former industrial use do not tie in easily with reported rapid drops in level unrelated to rainfall. I do not know how to think around that problem – unless we are forced to think the almost unthinkable- someone is using the water, perhaps unwittingly.

  17. andy arthur

    If it helps your investigation, this is marked on the 1959 1:2500 OS map as a “tank”. It doesn’t appear on the 1917 1:2500 sheet, so at least that places when it might have been constructed.

    1. Nigel Turnbull

      Thanks for that Andy. If you look at the top of page 1, there is a coloured map from the 1930’s that shows the Pool as a large dot but does not identify .it. The forest has been clear felled in this area. Previous maps showed this area as mixed forest and I suspect the Pool may well have been missed on them — either accidently or deliberately. The area was still clear in the 1970’s and seems to have been reforested (up to the power-line clearing) during the 1980’s. Nigel

  18. Robert Murray

    Photo of an oven of the East Plean Colliery they forgot to demolish.


    Apart from the valve pit/manhole on the edge of the trees I also canny quite get my head round why the pool/shaft entrance/pit/whatever had to be so big?
    Such a huge hole in the ground just to access a passageway?

    This puzzle has not been completely solved in my book.

  19. Robert Murray

    16 Jan was a frosty morning and all puddles were iced over up at Torwood. I ommitted to mention that there was no film of ice on the water of the ‘pool’ which ties in with the air shaft/warmer water theory. In fact the water was over-flowing out of the ‘pool’ from the removed brick at the south-eastern side. Quite a lot of flow actually.

    I have to keep mentioning that inspection/valve pit. Its not there for nothing. What could it possibly have had to do with an air shaft?

    1. David Hunter

      Hi Robert Murray you must take a look at Carbrooke dry pool (airshaft) It has the same inspection/valve pit as the blue pool with all pipe work on show?????

    2. Nigel Turnbull

      Robert, the manhole is still a mystery. It seems to line up with a short stub of 1” iron pipe that sticks out the bottom of the pool and points towards the arch.
      There may have been an outbuilding with a wood fired boiler that supplied steam via a shut-off valve 3 metre underground in the manhole.
      The steam could have been used to power maintenance equipment in the airshaft or if, when the Pit closed around 1910 and the shaft flooded, someone converted it to a Spa/Pool and the steam was for heating the Pool for a few hours before the gentry took their dip. Nigel

      1. David Hunter

        ok Dave is thinking out loud again Nigel! this is not closed the facts are the pit head at Plean cross road has coke kilens the buy product of coke is coal gas less than a mile away Carbrooke House has a gasometer FACTS!!!! The pit head (gasometer) and the blue pool are all the same brick and 99.9% sure they are all linked by tunnel. Why was the pit producing coke (coal gas)

        1. Nigel Turnbull

          Hi Dave. Hopefully we can meet up this year so you can give me a tour of the Plean Kilns which were, I think, next to Plean Number 3 Shaft. It would be good to get some photos. I have always assumed that these large Coking Kilns produced Coke to be used in Iron Foundries for smelting as it can burn at higher temperatures than coal. The gas is indeed a by-product which could either be sold to users in the immediate vicinity or simply feed gas-burners to heat the Kilns.
          I can’t imagine why there would be interconnecting tunnels. As for the bricks all being the same — they may have been sourced from the same nearest local brickworks. Nigel

  20. Robert Murray

    Was up there 16 January.



    Path from Torwood Castle churned up but firm due to the frost (though a quagmire on return walk due to higher temp – melting frost)

    Evidence of digging to N.W. of pool/shaft. At least two sites, furthest being up to 15m away from subject.

    Evidence of previously unseen foreign material white in colour (white clay?) within pool/shaft around the part of archway.

    Damaged/deformed shaped iron/steel key (approx. 2m + long) noticed lying beside inspection/valve pit to south-east of pool/shaft. Said pit still waterlogged from 600mm below top.

    Many cut lengths of birchwood lying around the pool/shaft.

    This inspection/valve pit must have something to do with the main subject.

    1. Nigel Turnbull

      Well spotted Robert. It was near the end of last year. I left before the excavations were filled in but I have some interesting photos. I will include them in the next update where I hope to orientate and scale the workings of quarter Colliery over a Google map. I am struggling for time at the moment but hope to have it done this month. Come the better weather, I hope to get some better video inside the arch to verify the latest theory that I think most of us have decided is the original purpose of the Torwood Blue Water Pool/Dog-leg Airshaft. Nigel

  21. James Milne

    Finally got to visit the area. I was working from memory and was on a tight schedule. It was peeing it down and blowing a gale – feet soaked running up the track to the wood from the south east. Didnt realise there were 3 lots of electrity lines crossing the area. got the middle one – through the dense gorse, through the soaking wet heather, disturbed 6 roe deer, lifted a woodcock and a male kestrel from feet from me – cracking view. But no pool – walked as far as the wall. Noted all the square depressions in the ground – are these subsidence related from the coal mining below ?

    Made my way back to the car soaked from the waist down ! Got back to the computer and realised my mistake – I was within 100m of the pool to the north. … Next time….
    Noted in the gorge near the road a large waterfall in full spate, with alot of concrete retaining walls around the area – anybody know reason for all the concrete – couldnt get a good view and didnt have time to have a mooch.

    Also went to Summerlee industrial Heritage centre. Bit disapointed by the girls description of the “coal mine” But my 3 year old son enjoyed it

    1. Nigel Turnbull

      Thanks James. You are not the first to make that mistake. I have never been in that clearing and have never seen the square depressions. You could be kicking off another investigation. Nigel

    2. David Hunter

      Hi James we are in Torwood and have never noticed this can you tell us how far up this is? Next dry day we shall take a walk up and have a look may get some pictures

  22. Gordon McFadyen

    Hi Nigel,.. Was a pleasure to finally meet you today up at the blue pool whilst doing a little on-site investigation with Davie(The Digger) Hunter,..that man loves a spade eh!!!. Yeh it was quite exciting to “Watch” Davie dig down on the NNW side of the pool about 1.5 mtrs from the perimeter to a depth of 2 ” feet approx to find the outside bricked wall of the arched tunnel,..pretty cool. I’m up for dumping out the water if at all possible,..but the pump can only drain 11 cube per hour,..what do you think Nigel,..Davies up for it,..quite an interesting couple of hours today.

  23. Robert Murray

    Just as a matter of interest if you look a bit more closely at the 1979 photo by Caroline Kerr you can clearly see the brick t the bottom left hand corner is more than one brick high. This supports the now lost boundary wall view proposed by Miles, then again …. the current brick is definitely flush – and finished looking – as if it originally was as it is now, then again …… maybe the wall above was added afterwards – just laid upon the original finish (the current situation) to make a safety barrier which was easily demolished over time and pushed into the flooded shaft.

    1. Nigel Turnbull

      Robert, we have a fairly recent and reliable report from John Gillespie that around 1954 there was a wall all the way round the Pool and the only way he could see the water was to pull himself up and look over the wall. He was 14 years of age. Nigel

      1. Robert Murray

        Thats right Nigel and Caroline’s photo confirms John’s recollection but as I’ve ventured ealier, considering the flushness of the present brickwork lip the wall must/might have been an ‘add on’.

          1. Robert Murray

            It was full of water up to about 2ft. from the top the day we were up there. Quite awkward to get over it to nosey about in the trees for more clues
            That key you took a photo of must signify the existence a valve in it eh? Why?

  24. David Hunter

    Hi Nigel this is so exciting I have followed what I can now call the MINE SHAFT from son off blue to the cross road plean back road found another shaft same brick but square and there is no tunnel on the other side. Knocked on the gentlemans door at the plean back road and the man tells me his house was the head pitt mans house this confirming COAL and the son of blue is conected (Dave is jumping up and down with excitment) all thanks to two pieces of bent iron. Surely that means it is date able??? How exciting is that

    1. Nigel Turnbull

      Sounds intriguing David — can’t wait to find out more.
      I am having a bit of a panic attack with the Pool Draining Party. I know that Miles made it all sound quite straight forward but he and his explorers are very experienced and have a lot of expensive equipment and know how to use it. My nightmare is of inexperienced people trying to keep their footing on slimy stinking mud while feeling their way through a dark tunnel to the edge of an 800 foot drop with no idea of how solid the roof of the tunnel is. I think more should be done with a remote camera.

  25. Andy Turnbull

    Mystery solved then – Only thing I’d say in defence of the comment >

    A local from Torwood village remembers the Game Keeper in 1960 describing how the pool used to have a Beehive roof that had since fallen in and the loose bricks were clearly visible on the bottom.

    There are images of air-shafts with metal grid roofs – that could be described as beehive shaped – perhaps the builders put one of these on as an extra safeguard. It would most likely have been a metal grid rather than brick though.

    Examples can be seen here >
    A shaft (image source http://industrialgwent.co.uk/Images/RV%20DarranOgilvieCollieryairshaft-1600.jpg ) from Ogilvie Colliery in Wales
    And here > A shaft (image source : http://waterwayroutes.co.uk/blog/2007/09/ ) from a canal tunnel

    1. Nigel Turnbull

      Andy, I have seen photographs of air shafts with domed metal grid covers. Whether Torwood Blue ever had one, we will probably never know but the one and only account of the Beehive Roof specifically refers to the Bricks at the bottom of the Pool being the remnants of the Beehive Roof. Nigel

    1. Nigel Turnbull

      Thanks Elaine but I can’t quite stamp it Case Closed just yet. If the video confirms the vertical shaft, I would still like to find a manhole cover with the name William Baird on it — and there are still Beehive Roofs and OG shaped guttering and possible change of use to account for. Nigel

  26. David Hunter

    The tunnel from the blue pool shaves pasts the Glenbervie roundabout (motor way side)under the bowling clubat Burnhead road,under the rugby pitch at Larbert High School and then picked up again in front of carron iron works clock tower and then under the carron.I have got as far as the houses in Laglees!!! It appears to be headin for the sewage works or the forth,I do not know what I am following with the dowsing rods but I am preety sure mines do not go in a straight line!!!!I am going to make a map of where I have been and post it on for nigel.

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