In this chapter, the main idea about a design tool and its object database system will be described. The design tool should improve design practice with respect to analysis and improving existing and planned urban environments. Preconditions for defining the design tool’s purpose are the determination of the “well-situated” urban elements, their impact on cognitive mapping, and the exploitation of the knowledge on cognitive mapping for the improvement of urban environments. This leads to the conclusion that an urban environment design, which takes of the process of cognitive mapping into consideration, will be experienced by most of the people in the same way. Investigations of this process result in a conceptual model of the tool by using elements of urban environments, their relationships and their dependencies. The theoretical background of the tool is based on design theory, cognitive science and computer science. Design theory and cognitive science will be used to develop the conceptual model. This conceptual model together with computer science will be the basis platform for tool development. The tool uses a schematic representation of urban environment, based on Lynch’s theory of “urban forms.” Lynch’s theory is crucial for the tool development because it explains elements of urban environments. Systematic investigation of urban environments and their characteristics are also important for the object schema of the tool. The tool will use an object database system, which help to represent and to handle the urban elements with their properties and relationships, with their natural semantics. The information represented in the database will be used to analyze urban environment with the aim to improve and control their visual quality.