Artificially structured materials, including superlattices, multilayers, amonohous alloys, quasicrystals, metastable crystalline alloys, granular metals, have been extensively studied in recent years. These man-made solids contain intricate structures and extra degree of freedom, which can be exploited for fundamental studies and tailoring properties. We present some examples of a wide range of phenomena exhibited by these materials as revealed by Mössbauer spectroscopy and other techniques. © 1990 J.C. Baltzer AG, Scientific Publishing Company.