Molecular self-assembly has recently undergone on explosive development, making possible the synthesis of many fascinating and complex structures using only relatively simple procedures. Over the last two decades, we have been showing that the simple combination of palladium's square planer geometry (a 90 degree coordination angle) with pyridine-based bridging ligands gives rise to the quantitative self-assembly of nano-sized, discrete organic frameworks. Representative and early examples in this field include square molecules (1990), linked-ring molecules (1994), cages (1995), tubes (1999), capsules (1999), and spheres (2004) that are self-assembled from simple and small components. By networking the discreet frameworks, we have also developed porous coordination networks (1994). In this article, we will disclose the structure of these self-assemblies as well as the chemistry of self-assembled “space” created in the void of the assemblies, where new chemical and physical properties of enclosed molecules are exhibited.