Behavior of spatio-temporal systems depends on real-time as well as spatial aspects. More and more safety-critical systems fall into this domain and thus raise the urge for formal specification and verification methods for this type of systems. For this purpose, we develop a diagrammatic language of Shape Diagrams that concentrates on the critical concepts and is usable by both engineers and scientists. We present two syntaxes, an abstract one based on hypergraphs and graph transformation systems that constitutes the abstract structure, and a concrete one given in terms of conventions for drawing diagrammatic pictures.