Geosites are significant geological heritage areas that serve as field laboratories for researchers. They offer insights into geological processes that have occurred from the past to the present and hold high potential for geotourism. To preserve and make geosites sustainable, their accessibility is a prerequisite. For this purpose, a model consisting of various parameters was developed in accordance with the Multi-Criteria Decision Making (MCDM) method, identifying 183 geosite areas that have been determined by experts and are subjects of literature. As a result, four evaluation criteria were established, including accessibility, access to service/attractiveness areas, scientific importance, and geomorphological features. Taking these parameters into account, a collective evaluation map was obtained using GIS-based AHP, drawing upon literature and expert opinions. The study concluded that the most critical parameter for accessibility to geosites is accessibility itself, accounting for 50% of the importance. Other parameters have influenced the accessibility of geosites in the following order of importance: 25% land, 15% scientific importance, and 10% service/attractiveness. Consequently, the areas where accessibility to geosites in Türkiye is most convenient are those with the highest road density. Road density, in turn, exhibits a pattern based on the characteristics of topography, population, and trade factors. Additionally, a parallel outcome emerged between areas that are more suitable in terms of these factors and the density of geosites. As a validation of the newly created model, the accessibility of Türkiye's areas recognized by UNESCO was found to be very high, indicating that the model is a suitable and convenient method that can be applied to different areas.