When we move around in our environment we assimilate the layout and the content of our surroundings – what things are located where, what are the paths that connect one place to another etc, and in doing so we form a mental map. We are now starting to understand the neurobiology of this map and in doing so are discovering the importance of the environment in shaping it: in particular, we are finding that some environments aid mapping and some hinder it. In this talk I will argue that poor mental mapping leads to an emotional state I call “spatial unease” – the feeling of not knowing exactly where you are in relation to your wider surroundings. This leads not just to poor navigation but perhaps, more broadly, to a poor sense of ownership and belonging with respect to the city. I will lay out some principles deriving from the neuroscientific study of mental mapping that may help reduce spatial unease and aid in the design of cities that are both easier and more pleasant to navigate.