New fieldwork at the Sanctuary of the Great Gods on Samothrace reveals flat arches in the Doric frieze of the Stoa, a structure built in the second quarter of the 3rd century BCE. In this lecture, Sam Holzman, Assistant Professor of Art and Archaeology at Princeton University, examines these keystone friezes, which predate similar examples in Italy by over 150 years and highlight a critical moment in ancient structural design, bridging Greek trabeated aesthetics with Roman architectural innovation. Holzman traces this evolution, from cantilever-based devices in Athens to plate-bande construction in late Republican Rome, showcasing the blending of form and function in the ancient Mediterranean.