"Educating about Biodiversity" is one of the major contemporary educational challenges, encompassing multiple dimensions related to the following domains: scientific (i), educational (ii), socio-cultural (iii), and even cognitive (iv). The term and concept of "Biodiversity" was coined in the 1980s by scientist Thomas Lovejoy (1941-2021) as a theoretical result of extensive field research experience. It was precisely on this important topic that I developed various educational initiatives in secondary education since the early 1990s. In those years, I conceived the project, later approved by the Friuli Venezia Giulia Region, entitled: "Biodiversity Experience Center for schools of all levels", which concluded in the 2007-2008 School Year. As Head of the "Addobbati-Brunner" Middle School in Trieste, a hub school recognized in the 1990s as a "Biodiversity Experience Center" by La.R.E.A. (A.R.P.A.-FVG), I implemented a multi-level educational project, starting from the illustration of the main ecological-vegetation typologies characteristic of a site in the Trieste Karst at the species, habitat, and landscape levels, and I made use of the documentation provided by satellite and aerial images, as well as the extensive existing literature. At the pedagogical level, I also developed a specific innovative model, based on the valorization of "direct and indirect natural experiences", according to diversified implementation methods. "in situ" and "ex situ". Over the following years, the educational program focused on adult citizens, consistent with UNESCO guidelines on the role and socio-cultural importance of "Longlife Learning." I involved the E.N.D.A.S. city association and the "Università della Terza Età" (University of the Third Age) to address the following two topics: one concerning the ecological and health aspects of “Lyme borreliosis”, a disease endemic to the Trieste Karst region, and the other involving the Ginkgo biloba tree, a true "living fossil" found throughout the city's public gardens.