It took me a while to find this old Masterpiece show. It was also a production about hiding art treasures. Parts of it are fictional but the background evidently wasn't.
"Frank Cottrell Boyce, bestselling author of Framed, explores the fascinating real-life history behind the story and adapting the book for television.
During World War II, Winston Churchill made the safety of the paintings in the National Gallery his personal responsibility. Art is often looted in wartime (that's how a lot of the paintings in the gallery got there in the first place), and he was determined that it wouldn't happen in London. The paintings were hidden in a vast cave, in a slate mine, a mile underground in the remote town of Blaenau Ffestiniog in North Wales. "
http://www.pbs.org/wgbh/masterpiece/framed/boyce.html
Either way it's worth a look. Netflix has it.
Masterpiece Contemporary: Framed
When London's National Gallery moves its treasured art collection to an abandoned mine during the museum's renovations, quiet curator Quentin (Trevor Eve), who's in charge of the operation, gets to know the eccentric residents of a nearby Welsh village. While the relocated masterpieces alter the villagers' lives, Quentin falls in love with a local schoolteacher (Eve Myles) in this family drama based on Frank Cottrell Boyce's children's novel.
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