The synthesis and aggregation behavior of cavity-containing facial amphiphiles is described. The molecules consist of a glycoluril-based rigid cavity functionalized with two water-soluble benzoate groups. By specific molecular recognition processes in water, the amphiphilic hosts self-assemble in a hierarchical process to form arrays of molecules. Depending on the counterions, these arrays can be assembled into well-defined aggregates of mesoscopic size. The size and shape of the aggregates can be tuned by variations in the size and substitution pattern of the cavities of the host molecules.