The cities actually seem to move without the author having to sit on his ass and describe everything. He paints his world not by telling you what color the buildings are, but by glancing over details, such as the way the characters interact within the streets or what kind of art is valued. Are the characters talking closely or openly, are they looking around or are they relaxed? Are they being noticed or ignored? What does the local music sound like? What do they drink? He trusts his readers’ imaginations, unlike so many fantasy authors who have to pull you aside and tell you what a tree looks like.