Virtual reality (VR) has been a non-negligible tool in education for several years, bringing numerous challenges across various areas involved in designing and executing immersive educational interventions. In spring 2020, our applied research project titled "Education in Collaborative Immersive Virtual Reality" was initiated to address some of these challenges. The project brought together experts from diverse fields, such as psychology, educational science, information science, English teaching, geography, and IT. Through a comprehensive and intricate design process, we successfully developed and evaluated educational programs in English as a foreign language (EFL) and geography using VR. Furthermore, we collaborated on an original software solution that enables real-time collaborative learning in the VR environment. Our project also integrated VR technology into an EFL university course, high school geography classes, and a distance bachelor program in information design. Identifying appropriate topics and instructional methods for VR implementation was crucial to achieving these results. We carefully assessed scenarios where VR truly adds value, avoiding hasty ventures into virtual environments without significant benefits. In the design, we focused on developing high-quality VR-based lessons to compare with real-environment-based classes of a similar quality (instead of sticking solely to their absolute equivalence. Such a setting required a meticulous approach in terms of research methodology. In this presentation, we aim to introduce and discuss the findings regarding the opportunities and limitations of VR-based education, along with its evaluation. Moreover, we will present the approaches and measures taken to empirically validate VR's impact on educational outcomes. By sharing the outcomes of our research, we hope to contribute to the ongoing dialogue on the integration of virtual reality in education, fostering a deeper understanding of its potential and the best practices for its implementation into formal and non-formal education.