The 21st century draws attention as a century in which environmental destruction continues, on the one hand, and efforts are made to prevent these destructions with holistic and sustainable approaches. Rapid and unplanned population growth, industrialization, informatics and industry 4.0 revolution, carbon emissions, ecosystem destruction, environmental pollution, global climate changes continue unabated. On the other hand, many institutions and organizations, especially the United Nations, are taking steps and setting goals to slow down this trend. The shores of Izmit Bay were examined in this study in terms of holistic and sustainable spatial use. In this field, where demands and usage needs are high but resources and potential are limited, it is clear that optimal and correct use is imperative, considering the future and future generations and environments. In the study, land use characteristics were determined and evaluations were made in terms of sustainable holistic basin management. Correct and sustainable use, as the most basic application subject of Geographical Science, which deals with the interaction between natural and human elements in a place, has been evaluated from a multidisciplinary perspective.