The Associazione Città dell'aria (Association of the City of Air), established in 2021, brings together Italian municipalities linked to the aeronautical sector by history, culture, sport or economy, to encourage the development of leisure and sports flying, in order to promote tourism and the region. At the request of the Secretariat of State for Tourism, the Republic of San Marino is dedicating a postal issue to this project. San Marino, through its Aeroclub, was the second signatory of “City of AirThe project aims to identify and define the role small airports, airfields and aerodromes can play to promote tourism and the territory. San Marino intends to increase flight tourism, a project to develop the runway of the Torraccia airfield has already been approved. This postal series involved the Aeroclub San Marino, the Aero Club d'Italia, the Piloti di Classe association, and the municipalities of Castiglione del Lago, Magione, and Passignano sul Trasimeno. The four values of 1.25 euro were created with the aid of artificial intelligence and are inspired by futurist Aeropainting.