The integration of advanced game engines and web technologies has transformed the intersection of culture, education, and gaming. This paper introduces Museatopia, an innovative virtual world framework designed specifically to become the Metaverse for virtual museums and exhibitions. Museatopia supports natural, user-friendly, immersive interaction, allowing, on one hand, the museum owners to easily curate their virtual presence with custom virtual exhibitions, and, on the other hand, the visitors to participate in rich cultural experiences. By combining digital content from various museums, Museatopia provides a dynamic cultural Metaverse, where even small museums can showcase and promote their content on a global scale without any digital skill requirements, greatly supporting their sustainability.