We provide experimental evidence of the mitigation properties of metaconcrete under blast loading. Mitigation is achieved through resonance of engineered aggregates consisting of a heavy and stiff core coated by a light and compliant outer layer. These engineered aggregates replace the standard gravel in conventional concrete. To assess experimentally the attenuation properties of metaconcrete, we have cast two batches of cylindrical specimens. The mortar matrix of the first batch consists of cement combined with a regular sand mix, while the mortar matrix of the second batch consists of cement combined with sand mix, fine gravel, and polymeric fibers. One of the specimens of each batch was cast with no aggregates, while the other two contained 40 and 60, respectively, randomly arranged 22 mm diameter commercially available computer mouse balls. We performed nondestructive dynamic tests by applying a 10 V amplitude periodic signal to one end of the specimens and measuring the amplitude of the transmitted signal received at the other end. We observed a remarkable 2 order of magnitude reduction in the amplitude of the transmitted signal in metaconcrete relative to conventional concrete.