Geodiversity can be described as the natural variety in geological, geomorphological, pedological, and hydrological elements in an area. The present study shows a geodiversity mapping of the urban coastal area of the province of Naples in order to assess its geodiversity potential and to support nature-based solutions (NBSs). This approach enabled a comprehensive understanding and assessment of biological and geological diversity, which constitute a priority for the landscape under investigation. This study focused on three types of ecosystem interventions: creation, restoration, and preservation. Each geodiversity unit was analyzed in terms of vegetation content to explore the following issues: correlation between the spatial distribution of physical and biological environments, assessment of biodiversity levels across the study area, and providing insights to improve NBSs for the local coastal environment. The results identified key spots for ecosystem interventions in the urban coastal area. Drawing upon this data, the study specifically examined municipalities southeast of Naples, at the foot of Mount Vesuvius, as they are highly urbanized areas experiencing significant momentum in urban regeneration projects. In conclusion, the study underscores the importance of the relationship between geodiversity and biodiversity and demonstrates the innovative use of geodiversity as a tool for effective land use planning and biodiversity conservation in dynamic coastal urban landscapes.