World War Two: The little-known role of a Welsh quarry
Looking at it from the outside, Manod Quarry in north Wales looks like any other abandoned quarry - dark, cold and a shadow of its former self.
But it played a vital if little-known role in protecting Britain's most valuable artwork during World War Two.
After Winston Churchill ordered the National Gallery's collection to be hidden in "caves and cellars", experts scoured the UK for a hiding place.
They found Manod Quarry in Blaenau Ffestiniog, and it revolutionised the way artwork is stored.
