August 27 2009 marks the 70th anniversary since the Treasury approved a £546,000 development of a World War II weapons plant - in 2009 it’s a naturereserve.

For years the secrecy surrounding the Rhydymwyn Valley Site, near Mold, served only to fuel rumour about what, if anything, could still be hidden in underground tunnels that once housed thousands of mustard gas shells during the height of production in the war years.

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