Many studies in cognitive psychology, human geography and artificial intelligence have investigated basic research questions of how humans navigate and orientate in space. While this research has generated very detailed models of specific determinants of human spatial processing, there has been rather little direct impact on applied fields dealing with the interaction of humans and spatial settings, most notably architectural design. The project “ArchWay – Architectural Design and Wayfinding Cognition” addresses several separating forces in architecture and behavioral science. Our basic approach is to investigate both the users of complex building settings and the architectural designers who envision these environments. On the user side we combine classic measures of spatial behavior and human spatial memory with attempts to model the real world task structure of a person navigating the complex, public buildings to find their desired goal location. The approach identifies environmental factors as well as internal cognitive processes that determine route choice preferences and strategies and, thus, shape wayfinding behavior. Real-life experiments and Virtual Reality studies will help us to assess how such features contribute to human wayfinding behavior. Measures from the architectural theory of Space Syntax (Hillier & Hanson, 1984) are currently employed to analyse the experimental settings and thus identify systematic relationships between building properties and human wayfinding behaviour, e.g., via newly-developed route-based measures of spatial properties. Regarding architectural designers our aim is to understand cognitive aspects of the underlying processes of designing for wayfinding. It is largely unknown how architects reason when they try to integrate wayfindingfriendly factors into their designs. We uncover the relevant aspects of wayfinding issues in architectural design processes by capturing design knowledge, design guidelines as well as process models of wayfinding design. Interviews and focused experiments on design behavior help us to understand specific tool support requirements for designing wayfinding-friendly environments. The presentation of this paper at IAPS 2008 will provide an overview of the different techniques employed in the first three years of this 6-year-project and highlight open research questions connecting the interests of cognitive scientists, environmental psychologists and architectural design researchers.