Here's what Trippy members say about University of Warsaw Library:
"Depends on what you like,but I think the Warsaw Old Town is an ok option,from where you can cross the river and go to Praga (an artistic and at the same time pathological neighborhood:P ) and then come back to the Old town and walk down by the river to the rooftop of the University of Warsaw Library, where there is a garden and a great view." See More