The Federation of Damanhur is an Italian religious organisation recognised by the United Nations as "a model for a sustainable future," according to
an impeccable source their own website. They keep pretty much to themselves most of the time, dedicating their lives to "ritual tradition, social realization, experimentation and dynamics, and individual inner refinement" - according to another impeccable source Wikipedia. They also dedicate themselves to other matters which have attracted various forms of attention: cultish behaviour; the building of "the eighth wonder of the world" - actually just a rather pretty temple; and naked time travel involving German pop singers
The whole thing was started in 1975 and now has about a thousand members in its 500-hectare property.