The Secret Valley

The Rhydymwyn Valley History Society was founded in May 2008 and its core interest is the operation of the Valley Works at Rhydymwyn and the involvement of Tube Alloys in the site. It is a story of over 2,200 people in wartime directed labour, and billeting, the enfranchisement of female labour, the involvement of common people in a worthy, but distasteful, duty. It is not, in any way, an attempt to glorify war or to condone militarism.

The information on this site is contributed by members of the Rhydymwyn Valley History Society. We currently have over 1,200 members and new members are always welcome! We welcome everyone who wishes to become involved, irrespective of age, gender, sexual orientation, race, colour, ethnicity, political persuasion, religion or belief.

Meetings are held each month and take place in the Visitor Centre on the site.

Officers 2017-2018

Opening Hours

The Rhydymwyn Valley Site is open to members for managed access on weekdays from 8am to 6pm and at weekends from 9am to 5pm (holidays excluded).


The Rhydymwyn Valley History Society welcomes visitors from schools, societies and any other interested parties. We show movies, tell you about the site and will take you on a tour which will include taking you just beyond the threshold of the tunnel system.

We also make many visits to groups and societies throughout the area, giving illustrated talks at their meetings! Contact us for further information.

Contact Us


Rhydymwyn Valley History Society
Visitor Centre
17, Nant Alyn Road

Guest Book:

Guest Book


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We have ambitious plans which need funding. Our sole income, except for occasional grants, depends on donations (most of which come from Open Days and Guided Tours). The residue comes from initial subscriptions and annual donations from our members. We ask that, if you think we provide value, you support us further by contributing?

Web Site

The Rhydymwyn Valley History Society is funded by:

Heritage Lottery Fund Subterranea Britannica Flintshire County Council Welsh Government
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