Metaphor plays a key role in structuring our understanding of the world. Professional designers heavily rely on them to obtain high-level control over their designs. Therefore, future Computer-aided Design (CAD) systems are expected to support metaphor-based design. In this project, a computational system that is capable of generating metaphor-based designs was constructed and tested. The context for the project is that of Japanese rock garden design - a traditional practice of landscape design which is strongly associated with metaphoric interpretations. The system demonstrates that we can implement metaphoric design capabilities within digital systems.