Detail of the 600-year-old Fra Angelico fresco of a crucifixion that is being restored at a convent outside of Florence.Credit... Supported by By Elisabetta Povoledo Photographs by Clara Vannucci ...

When Steven Woloshin, an American doctor, first saw the 600-year-old fresco of the Crucifixion by Renaissance master Fra Angelico inside a cloistered convent in January last year, he was blown away.