The best non-fiction book I have ever read while visiting Europe is "Is Paris Burning?" by Larry Collins and Dominique Lapierre. If you are going to the City of Lights and want to take a book or get one there, this would be an excellent choice, regardless of whether you are interested in World War II history.
Humanity is fortunate to have Paris. The Nazis wired key structures--every bridge across the Seine, Notre Dame Cathedral, the reservoirs feeding the city, every major manufacturing facility--with explosives and planned to leave the city in rubble, like they did with Warsaw, as the Allies closed in. The book's title comes from none other than Hitler, who screamed the question in a rage at his commander in Paris, Dietrich von Choltitz. Von Choltitz was no softy but a brutal German general who was trained to win victory for Germany regardless of the cost and to pledge loyalty to his fuhrer. Why von Choltitz defied Hitler, thereby saving Paris, makes a compelling story. (I do not want to spoil the story.) I have visited Paris twice. After I read this book, I was grateful that Paris is there, a beacon of beauty, like the Eiffel Tower.
The book is a bit long, the product of two aggressive investigative journalists, it's only flaw. But it is compelling and definitely worth reading. Visit Shakespeare & Co. on the Seine to pick up a copy.