Abstract: Tanks for storing materials, especially liquid and semi-liquid materials. The tank wall is formed of a plurality of arcuate panels, each fabricated from vertically stacked precast concrete panel sections, which are joined by vertical pilasters, each pilaster formed from precast concrete pilaster sections. The wall is prestressed by tensioned tendons disposed on the periphery thereof. Each of the pilasters are supported by a separate footing and the ends of the arcuate panels are likewise supported on the footings. The footings are interconnected by a novel stabilizing structure to withstand seismic loading. These as well as numerous other novel structural features provide for a storage tank of modular construction, which is strong, stable and versatile; which may be constructed in a facile manner; and which may, if desired, be easily dismantled for relocation.