The Sanctuary of Zeus is the focus of the Mt. Lykaion Excavation/Survey (University of Pennsylvania, University of Arizona, and 39th Ephorate of Prehistoric and Classical Antiquities). It was described by Pausanias as a sacred place of pan-Hellenic significance, with stadium and hippodrome in which athletic games were held, a sanctuary of Pan, and a formidable temenos and altar of Lykaion Zeus. In picturing human activity on this mountain during ancient times, it is not adequate to treat the mountain as if it were simply a tall, symmetrical, and handy edifice within which rock contents are irrelevant, for the geology within Mt. Lykaion significantly influenced what was built on it, and where! There are contemporary reminders of the ‘power’ of the site, including the devastating April, 1965, Megalopolis earthquake, the epicenter of which was merely 4 km away. In fact, there are active normal faults within the sanctuary. However the primary geoarchitecture is that of the Pindos fold and thrust belt, fashioned largely in Cretaceous through Eocene. Mt. Lykaion's dome-like summit is a thrust klippe separated from underlying nappes by a major thrust fault (Lykaion thrust), the subhorizontal trace of which encircles the mountain creating a subtle bench in the landscape coinciding closely with archaeological and natural elements important to the sanctuary (e.g., stoa, seatwall, fountains, trails). Late Jurassic through Eocene ‘Pindos Group’ formations are stacked and repeated by the thrusting. Inter-relationships between bedrock, structure, and archaeology are revealed in a ‘geoarchaeological column,’ which displays positioning of elements in relation to the thrust, and orientations of rock formations in relation to flat patches in otherwise steep, rocky country, which became sites suitable for placement of hippodrome, baths, temenos, horse pasturing areas, etc. Worked limestone blocks are locally derived and can be matched with formations. The compelling high elevation of the ash altar is testimony to residual crustal buoyancy achieved through ‘Pindos’ crustal shortening, and the steep processional ascent to the altar speaks to regional active normal faulting and rapid erosion.