The Macchiatonda Shoals are located along the central-southern coast of the Lazio Region, specifically between the municipalities of Montalto di Castro and Tarquinia. The site encompasses a vast expanse of sea and sandy coastline characterized by the presence of rocky seabedsand a meadow of Posidonia oceanica, a marine seagrass that builds dense underwater carpets. The site also features numerous rocky habitats, including coralligenous formations composed of corals and calcareous algae, as well as vertical sea walls that host numerous species of invertebrates and fish.