As the name suggests, the 4KARST tourist products connect four types of karst (KRAS/KRŠ is karst in Slovenian/Croatian) and their four interpretation centers with four polygons i.e. interpretive heritage sites. Through the 4KARST products, visitors can immerse themselves in experiencing and exploring the KRASn’KRŠ story of the wonderful karst landscape. 4KARST products connect and market the joint tourism offer of all four interpreted types of karst. The products examine common topics, such as geodiversity, biodiversity, humans in karst, and others. Four integral 4KARST tourism products were proposed and developed in the project: