The Mediterranean is often studied through its iconic coastal ecosystems, such as Posidonia seagrass beds, lagoons, and densely populated coastal zones. However, more than 80% of its surface area consists of offshore zones and deep-sea environments, including submarine canyons, abyssal plains, and seamounts. Long considered remote from human pressures, these ecosystems are now emerging as strategic areas. Do they represent the next major challenge for science and conservation, requiring appropriate governance and protection strategies?