My project traces the emergence of monumental freestanding arches in Roman port cities during the early imperial period and how these works perform a “spectacle of the border” through their siting, construction, design, and transformation via artistic representations. Territorial expansion and maritime trade increased the movement of goods and people, resulting in harborscapes characterized by symbolically loaded building types such as lighthouses, temples, amphitheaters, and arches. Erected on moles or piers throughout the Mediterranean, harbor arches served both practical and aesthetic functions, acting as landmarks for approaching sailors and projecting an image of Roman influence to diverse travelers and local inhabitants. The very act of building coastal arches was itself a spectacle, requiring specialized technology, employing local workers, and reinforcing community identity.