The site of Tiwanaku is thought of as the center of a civilization of the same name that exerted its influence over the southern Andean region from around 300 B. C. when it emerged to about A. D. 1100 when it collapsed. The architecture of Tiwanaku today is reduced to several eroded mounds, outlines of courtyard structures, weathered uprights, fragmented walls, foundation stubbles, and jumbles of building stones but not a single standing, original building. It is argued that before this architecture can be understood and its anthropological and cultural significance properly appreciated, it first has to be reconstructed. The reconstruction of Tiwanaku architecture, in turn, requires an understanding of what the design principles were that gave Tiwanaku architecture its identity. Many building blocks and fragments are analyzed for the purpose of identifying the design features typical of Tiwanaku architecture, and in search of clues to their bond to other stones and to their initial appurtenance to some larger configuration. Several partial reconstructions are presented.