The seabed remains largely unknown. Compared to terrestrial landscapes, which are m accessible and familiar, most of them remain unexplored, being an enormous challenge for scientific research fica. ESTE book presents the underwater landscapes of different areas of the peninsular Mediterranean: unique and little-explored seabeds, formed by crinoids (exclusively marine animals) and maërl (aggregations of calcareous marine algae), which are between 20 and 200 meters deep.