A foundation system for a tower, such as a wind turbine, includes a central hub assembly, a plurality of post-tensioned concrete beams, and an anchoring system associated with each beam. In use the foundation system is arranged so that the bottom surfaces of the concrete beams bear on soil and the anchoring is disposed within the soil. The beams can be inverted bulb-T beams having post-tensioning cables inserted there-through and cooperating with an oppositely disposed related beam. The central hub assembly can include a plurality of stacked disk elements or steel frame elements that are post-tensioned together to form a single hub structure.