The paper analyzes transmedial phenomena from a perspective rooted in the semiotics of culture. It is structured into three case studies and an explanation of their applied dimension. The latter involves a digital educational platform, Education on Screen, developed in collaboration with the Transmedia Research Group at the University of Tartu. The first case study involves close reading of a spatial motif (emptybeach) that lies at the core of an Estonian short novel, along with its cinematic and theatrical adaptations. The second case study proceeds not from an artistic text but a historical event as a transmedial text in cultural memory. The corpus consists of a novel, a film, and a painting that mediate the overseas flight of Estonians during the World War II. The analytical focus is on the representations of the seashore in these texts and on the formation of a new mnemonic whole based on these transmedial variations. The final case study explores the applicability of transmediality on the descriptive metadata of digital archives, which have a growing role in the formation of contemporary cultural repertoires. Following this path, the paper contributes to the research on cultural dynamics and to updating the transmedial model of culture, especially by balancing the divergence and convergence processes that underlie cultural sustainability.