Canaletto masterpiece returns to Wales 80 years after it was hidden in slate mine

The Stonemason’s Yard, painted in about 1725, is unusual for Canaletto in that it depicts ordinary people. Photograph: The National Gallery, London

During the second world war, the painting was transported 250 miles from central London to north Wales to be hidden in a slate mine, tucked away from the perils of Nazi invasion and Luftwaffe bombings.

Eighty years on, there has been a sort of homecoming for Canaletto’s masterpiece The Stonemason’s Yard as it returns to form the centrepiece of a show opening this week at the National Library of Wales in Aberystwyth.