Transnational nominations on the World Heritage List based on the project "The Great Spa Towns of Europe" are presented in this paper. The goals of the work were to investigate the importance of preserving cultural heritage, to investigate the purpose and goals of the project "The Great Spa Towns of Europe", to point out the possibility of networking during the protection of cultural heritage, and to make a proposal so that Croatia could network its spas according to the example of good practice. The purpose of the work is to point out to individual communities the importance and ways of preserving cultural heritage, and at the same time highlight the possibility of networking with other countries. Cultural heritage represents the totality of the values of a certain environment, which consists of material assets of cultural, health and historical significance, as well as non-materialized forms of human creativity and the past. In the UNESCO Convention for the Protection of World Cultural and Natural Heritage, cultural heritage refers to monuments, groups of buildings and localities of historical, aesthetic, archaeological, scientific, ethnological or anthropological value. For the sake of all the mentioned values, its preservation is very important. In order to carry out an effective action aimed at preserving cultural assets, it is very important to invest a lot of effort and time in preparation and planning. When preserving, it is first necessary to determine goals, gather interested participants and create an action plan. It is extremely important that the management of cultural heritage is guided by the concept of sustainable development, given that the goal is preservation for future generations. The very goals of sustainable development promote the preservation of heritage and raise awareness of its development. A separate part of cultural heritage is represented by transnational nominations that refer to goods that are spread over the territories of different countries. Such an example is the project "The Great Spa Towns of Europe". It represents part of the world heritage, which consists of 11 famous historical spas and cities in seven countries, inscribed on the World Heritage List on July 24, 2021. Namely, it is about the phenomenon of European spas that had their greatest rise in the period from 1700 to the thirties of the last century. The example of the project "The Great Spa Towns of Europe" can be copied to Croatian continental spas. The basis for their networking is the common but also different characteristics of each individual spa, their proximity, but also numerous technological innovations as well as numerous investments in their renovation and capacity expansion, which will bring them to the level of renowned historical European spas.