The issue of public space in cities has recently become an increasingly discussed motive not only among architects, but also politicians and ordinary citizens. This is a topic that reflects the satisfaction and quality of life of all residents. Public space can be characterized as a space accessible to people at any time of day, designed for a wide range of different age groups, social classes, genders, and races. The perception of urban space by its inhabitants is an important part of research into urban structure and spatial planning. The process of mental mapping makes it possible to define potentially dangerous or otherwise critical areas of cities. Mental maps could reveal the specifics of fear of a defined group of people, including their reasons. Addressed identification of stressors is a key basis for increasing urban satisfaction and security. The paper presents a case study of positive and negative localities based on mental mapping in a typically medium-sized city in the Czech Republic, in Chotěboř.