"Madonnas of Leningrad" by Debra Dean

This is a very profound little book - about memory and longing.  It has two plots.  The historical plot took place in Leningrad at the Hermitage in the Second World War when a young woman packed all the precious paintings to preserve them from damage during the bombing.  She memorizes the paintings and their location in the large museum - creating a "memory palace". She recalls the details of each painting, and in later life she can bring up every small detail even through the haze of dementia.  In the contemporary plot, she is an old woman at the wedding of her grandchild - still living a double life through her memories of the Hermitage and her life as a wife, mother and person.