Synchronization is the essential function of many biological networks. The synchronization of pace-maker cells in the heart creates a pulse that drives blood throughout the body. The synchronization of specialized neurons in the brain creates a circadian clock that keeps the body in time with the day. It is difficult to determine the origins of this synchrony, in part, because biological networks are typically complex and impossible to observe. In particular, the topological structure of many biological networks remains unknown. Furthermore, it is costly to conduct experiments capable of determining the function of observed network features. As a result, theoretical explorations of emergent synchrony are called for. We use optimal control theory to build networks that maximize synchrony. Analysis of these optimal networks allows us to identify topological features that promote synchrony.