In a recent underwater archaeological survey conducted along the coast north of Rome, near Santa Marinella, at a depth of 1.5 meters and 90 meters from the shoreline, we identified a significant assemblage of organogenic sandstone (macco) ashlar blocks. These blocks were arranged in a double parallel row extending approximately 5 meters in a NW-SE orientation, parallel to the coastline. The arrangement of the blocks delineates an internal space filled with stones, forming a structure reminiscent of a mole. The ashlar blocks were positioned in two distinct manners: the stretchers (Greek: διάτονοι) were placed with their longer sides facing outward, while the headers (Greek: ὀρθοστάτης) were arranged with their shorter sides facing outward, contributing to the structural reinforcement. Midway along the structure, a narrow canal formed by a double row of ashlars provides a connection between the internal space and the exterior, facilitating water circulation and mitigating the risk of silting in the port basin. The external mole continues northwest, incorporating additional blocks and natural rocks, which together form an L-shaped configuration. The area protected by these moles covers approximately 3,000 square meters and is located in close proximity (130 meters) to the sixth-century B.C. Etruscan temple at Punta della Vipera. These findings represent the earliest known evidence of a utility landing site associated with the Etruscan temple.