Cultural heritage is a particularly significant resource in creating tourism. When a local community recognizes its cultural heritage (small historic towns, buildings, castles, and forts), it is possible to create new value to meet the needs of tourists, using the principles of a circular economy. Adapting, reusing and restoring heritage sites can contribute to the revitalization of the local economy by creating jobs (increased employment), increased spending, economic development, etc. Adaptive reuse, as one of the principles of a circular economy, represents how the circular economy can pave the way to create new tourism products. The three basic principles of sustainable waste management are reduce, reuse, and recycle (3R). This paper tackles the reuse principle by analyzing case studies involving the application of a circular economy to cultural heritage in the Kvarner tourism destination (Croatia) in the context of reusing resources to create a sustainable destination. The goal is to determine to what extent the reuse of heritage sites makes them useful for the local community, and for tourists to stay in the destination. The research showed positive examples in the Kvarner tourism destination, primarily of a cultural tourism nature and that were achieved in the last ten years; however, the conclusion is that this is still insufficient. By aggregating knowledge and research results, the paper emphasizes the importance of applying the concept of the circular economy to cultural heritage in tourism destinations, with special emphasis on the role of all stakeholders in creating sustainable heritage tourism (local self-government, destination management, local population, and entrepreneurship).