The application of digital technologies for the accessibility of cultural heritage sites is an emerging area of research that presents relevant design challenges. In this regard, the potential of virtual reality (VR) is increasingly highlighted to guarantee the universal right to enjoy cultural heritage to visitors with different accessibility needs. This study provides a contribution to advance knowledge and practice in this area by presenting the design process and findings of a research project aimed to develop a compensatory solution through VR for improving the accessibility of cultural heritage sites for visitors with mobility impairments. For this research, the Scenario-Based Design method (SBD) is applied within a User-Centered Design approach to identify user requirements of the VR interface. Based on this method, different personas and corresponding scenarios are designed to represent the needs, motivations and behaviors of the main user groups of the compensatory technological solution. Further, the SBD is used in the prototyping phase as a tool for co-design activity, which involved users with specific accessibility needs, designers and other stakeholders to identify the requirements of the VR application. The paper presents the findings of the co-design relating to the functional and experiential requirements and discusses the methodological and practical implications to support the use of this approach for the development of digital solutions for cultural heritage accessibility