"METROPOLIS 2021 - Street Synthesis" was planned as an active city exploration and urban learning between parks and urban canyons: Participants were to experience the City of Wiesbaden in an active and intercultural way and explore the questions: Can I influence the city as much as the city influences me? Metropolis was also the first youth encounter in 15 months in Covid-19 times and took advantage of a suddenly opening window of opportunity to carry out the project and give the participants an intercultural experience and reward for the courage to participate in a transnational project. To this end, the goal was to send Metropolis into the city, but effectively create a microcosm in which the relatively large number of participants have minimal contact with people outside the project. To this end, the project utilizes the youth nature campground and conducts 98% of the program outdoors. The goal is also to create the most intense interaction possible with the least risk of infection. Soft skills such as teamwork, decision-making, communication and empathy are to be made tangible for the participants. The learners are motivated to take active, interactive and communicative action. The actions should enable a change of perspective among the participants and challenge them. The project helps the young people to enjoy learning and cooperating. A discarded goal to perceive the city with different eyes and to discover new possibilities to creatively appropriate this living environment was replaced by simulating a society within the camp, including its own social network, its own architecture and of course its own cultural activities. Synthesis is a thematic suggestion, which should inspire the themes of the artistic processes of the young people, as well as serving as a metaphor for how strong a union of creatively motivated young people can be and can enliven the city. Experiences, creativity, imagination, curiosity and joy are released during the artistic workshops. The use of new and traditional media enables participants to learn new ways of expression and to enter into active communication with, influence, and creatively appropriate the world in which they live. The possibilities of experience and action are manifold in a camping project and the opportunities for personality formation should be easily and effectively perceived. In the youth meeting METROPOLIS 2021: Street Synthesis should participate a total of 60 young people aged 14 - 21 years, from the countries Georgia, Poland, Ukraine, Romania, Moldova, Turkey, Spain and Germany. Turkey and Ukraine were not able to participate in the project unfortunately.