The Borromean rings
Borromean rings are well known to topologists, in particular to those interested in knot theory. They are three rings linked together, but if we remove any one of them the other two fall apart. They are named Borromean because are present in the emblem of an Italian family of the Renaissance: The Borromei. The authors of this paper illustrate some mathematical properties of these rings and lead us in an interesting tour through the places where we can see some Borromeo's emblems where the rings are represented. In particular Isola Bella in Lake Maggiore in northern Italy and Milan.
scientific article; zbMATH DE number 1233995