The platform, one of architecture’s essential forms in both design and theory, is shown to have purposes and meanings that are simultaneously practical and representational. The study begins with Louis I. Kahn’s design for the Salk Institute. After that, his deep interest in ancient Greek architecture provides a gateway into the Classical period of ancient Greek architecture. Temples, tholoi, and other types are interpreted as equivalent articulations of the platform theme. Where relevant, the ideas and work of other modern architects are considered, Louis Barragan and Le Corbusier particularly. Tectonic issues are addressed, but more largely matters of spatial and topographical definition. The built work’s interplay with forces of the natural environment, especially seasonality, is also addressed, particularly the moods that arise from this interplay. The study materials include the architects’ statements, ancient poetry, art, and myth. Boundaries between categorically distinct types are crossed in order to describe the platform’s polysemy and its several kinds of articulation.