Many of today's organizations already have a strong integration of groupware systems in their IT-infrastructure. The shared databases of these groupware systems form organizational memories, which comprise the complete knowledge of an organization collected over the time of its existence. One key problem is how to find relevant knowledge in continuously growing and distributed organizational memories. The basic functionalities and mechanisms in groupware systems are not sufficient to support users in finding required knowledge. Topic maps provide strong paradigms and concepts for the semantic structuring of link networks and therefore, they are a considerable solution for organizing and navigating large and ontinuously growing organizational memories. The K-Discovery project suggests applying topic maps to groupware-based organizational memories to create knowledge structures and address the mentioned challenges. Visual navigation capabilities to exploit the created knowledge structures are based on hyperbolic geometry concepts and provide users with intuitive access mechanisms to the required knowledge.