We'll shortly join the Grand European river cruise, so perhaps this is not so relevant to your quesation.
We wanted to develop a "feel" for Eastern Europe, terra inconita for us. Thus we've read Ivo Andric's Nobel-winning Bridge over the River Drina, Tim Butcher's The Trigger (in which a veteran Bosnian War correspondent retraces the steps of Gavrilo Princip, the young man who assassinated Arch Duke Ferdinand of the Austro-Hungarian Empire, touching off the First World War) and two of the three volumes that Patrick Leigh Fermor wrote in describing his epic trek from the Netherlands to Istanbul (starting in 1933, when he was just 18 years old).
On the boat, we plan to read Profs. Istvan and Magdolna Hargittai's Budapest Scientific: A Guidebook, which exhaustively treats "the visible reminders of science and scientists in Budapest."
And completely irrelevant but seeming interesting, we also plan to read Umberto Eco's Numero Zero on the boat.
Finally, since we are broadly considering culture, let me divert from literature to advise that Leon Askin (https://en.wikipedia.org/wiki/Leon_Askin) is a hugely BIG DEAL in Vienna, where we hope to find the several monuments erected to his memory. Vienna knew him as an accomplished actor. You might know him for his sizzling portrayals of Nazi General Burkhalter on the old Hogan's Heroes TV show (https://en.wikipedia.org/wiki/Hogan%27s_Heroes).