Building 45 is situated on the Rhydhymwyn Valley Gas Works site. This building was used in the initial research into Britian developing the atomic bomb. Codenamed ‘Tube Alloys’. Klaus Fuchs and Rudolf Peierls were the lead scientists involved. The photo shows the doorway that leads into the building. To me this was a seminal moment in its history. Making that step from one weapon of mass destruction to another. the year 1942.