The CLEO project, funded by the Erasmus+ program, organises a Summer University at the University of Belgrade in Serbia, between September 10-16, 2023. It is destined for students from the project partners institution, including Central European University. The other project partners are the University of Belgrade (Serbia), ARMES (Italy), the University of Akureyri (Iceland), the University of Patras (Greece) and the University of Louvain-la-Neuve (Belgium).