Gas Boys, Gas!

During WW1 chemical weapons were introduced and one of the worst was mustard gas, which really wasn’t a gas, more of an oily liquid which was dispersed as an aerosol cloud. Mustard gas is a blistering agent causing very painful skin blisters, blindness and if you inhaled it the gas would cause untold damage to your lungs.

Any country that had significant military ambitions could not afford to ignore the possible use of chemical weapons during a conflict. Not only did they have to be prepared to defend against the use of such weapons but sadly they also had to be able to retaliate if they were used. And so after WW1, heading into the 1930’s with the possible threat of an another conflict in Europe production of mustard gas in Britain was considered necessary, if only to act as a deterrent.

So that brings me to my latest trip out. Not much more than 20 miles from where I live in North Wales, lies a secluded valley which housed a secret, at the time, factory to store and weaponize the gas that was manufactured elsewhere. In 1939 work commenced to create tunnels in the limestone cliffs to store the product.

E-M1MarkII OLYMPUS M.9-18mm F4.0-5.6 1/8 sec at ƒ / 8.0 ISO 200

The valley is long and narrow, ideal for splitting the site into zones which served to isolate the hazardous stages in the production of the weapons.,-3.1867136,2153a,35y,90h/data=!3m1!1e3

Secrecy and a compound mentality meant that many workers were unaware of what was going on outside of their specific work area.

E-M1MarkII OLYMPUS M.9-18mm F4.0-5.6 1/60 sec at ƒ / 8.0 ISO 200

Access to the site in the present day is by controlled access but once you are in you are more or less free to roam around the valley. Building are open and the first one I came to was a great big shed.

E-M1MarkII OLYMPUS M.9-18mm F4.0-5.6 1/20 sec at ƒ / 8.0 ISO 200

There are 3 buildings like this and inside they are cavernous, just a great big shell with limited light streaming in from the open doorways.

Sound inside here echoes and even the drip of water is accentuated. press the play button and you’ll get to hear my dulcet tones echoing around the building.

Sorry about the YouTube link. It was the only way I could embed the sound. For some reason the WordPress Block Editor would not play the link to the sound of the echo.

At this time of the year it’s very quiet on site. I only saw a couple of guys working on the culvert that was built to channel the river that flows through the valley.

Once past the larger cavernous buildings I came to an area that had low brick buildings.

E-M1MarkII OLYMPUS M.9-18mm F4.0-5.6 1/100 sec at ƒ / 8.0 ISO 200

During construction of the site over 100 specialised buildings were constructed. Look closely at the building below. You can still see traces of the paint used to camouflage the squat brick buildings during wartime.

E-M1MarkII OLYMPUS M.9-18mm F4.0-5.6 1/30 sec at ƒ / 8.0 ISO 200

Some buildings are closed for safety reasons, others like the one below, because it house bats which are a protected species in the UK,

E-M1MarkII OLYMPUS M.9-18mm F4.0-5.6 1/30 sec at ƒ / 8.0 ISO 200

One is closed because of the smell from a chemical (I believe it’s Carbon Tetrachloride) which was used on site.

E-M1MarkII OLYMPUS M.9-18mm F4.0-5.6 1/60 sec at ƒ / 8.0 ISO 200

Chemical weapons production ceased in 1945 but the site was used to store mustard gas, including captured German versions, until 1956.

E-M1MarkII OLYMPUS M.9-18mm F4.0-5.6 1/30 sec at ƒ / 8.0 ISO 200

By 1959 all stocks of mustard gas had been destroyed and the site was decommissioned in 1960.

E-M1MarkII OLYMPUS M.9-18mm F4.0-5.6 1/80 sec at ƒ / 8.0 ISO 200

All of the buildings that are open are just empty shells.

E-M1MarkII OLYMPUS M.9-18mm F4.0-5.6 0.6 sec at ƒ / 8.0 ISO 200

They are all painted the same uniform colour and on the walls of nearly every building I visited you could see the letters ABCD spaced out.

E-M1MarkII OLYMPUS M.9-18mm F4.0-5.6 3.2 sec at ƒ / 8.0 ISO 200
E-M1MarkII OLYMPUS M.9-18mm F4.0-5.6 1/40 sec at ƒ / 8.0 ISO 200
E-M1MarkII OLYMPUS M.9-18mm F4.0-5.6 0.5 sec at ƒ / 8.0 ISO 200

Water is starting to ingress in some places but considering the age of the buildings it’s not to bad.

Nature is starting to take over and I found this building where the brambles were creeping over the window.

E-M1MarkII OLYMPUS M.9-18mm F4.0-5.6 1/10 sec at ƒ / 8.0 ISO 200

The building truly have been stripped of whatever they contained during the war years and beyond. I found this light switch at the entrance to one but that’s about it. nothing industrial. I suppose due to the nature of the work they couldn’t really leave anything behind when the site was decommissioned

E-M1MarkII OLYMPUS M.9-18mm F4.0-5.6 1/5 sec at ƒ / 8.0 ISO 200

There is some grafitti, not much but I found this interesting sign in one of the buildings

E-M1MarkII OLYMPUS M.9-18mm F4.0-5.6 1/10 sec at ƒ / 8.0 ISO 200

“Cleanway to Canteen”. I suppose due to the nature of the work there must have been some form of decontamination for the workers. But the room give no clue to what it’s true purpose was.

So what of the site today? In the 60’s it was used as cold war storage site for emergency supplies. In 1994 the site was officially closed. Then came a period of work to remove buildings and clean up the site in accordance with the Chemical Weapons Convention.

Today it is a dedicated nature reserve managed by North East Wales Wildlife. The Friends of Rhydymywn and the Valley Archaeological Society are working to develop the historical aspects of the site. A visitors centre has also been constructed.

I couldn’t hope to tell you everything about Rhydymywn in this short blog post but if you are interested and want further reading follow the link to the Rhydymywm Valley History Society

That’s it from me, as always Stay Safe – Mike


11 thoughts on “Gas Boys, Gas!

  1. Very interesting post. They should have used it to store all that PPE and saved the country a few million! As for embedding the video, I’ve had no trouble (with and without sound), so I’m not sure what’s happened there. Great echo though!

    Liked by 1 person

Comments are closed.

Create a free website or blog at

Up ↑

%d bloggers like this: