What does a no-go zone mean, and if it is an inaccurate term, what words can we use to describe a well-known reality that few would dare deny since the Amsterdam pogrom and the Hamas protests? The above dilemma is what Viktor Marsai, Omar Sayfo, and Kristóf György Veres try to unravel in their book Whose Space Is It? Parallel Societies and Urban Enclaves in Western Europe, published by MCC Press.