The word "triskelion" comes from Greek "tri-" (meaning "three times") and "skelos" (meaning "leg"). It is used to denote a three-legged motif or design: it has the property that it looks the same if you rotate it through 120 degrees. It is used in the flag of Sicily and in the flag of the Isle of Man. In both cases the triskelion appears literally – and somewhat unnervingly – as three legs. In other cases of the motif, the three "legs" at 120 degrees are just abstract designs, very often three spirals.

The name "Triskelion" has also transferred from the simple motif to various areas of the arts. For example:

• As a fictional building used by the intelligence/defence agency S.H.I.E.L.D. in Marvel Comics,

• As a fictional, trinary starlit world depicted in Star Trek

• As the name of a non-profit arts organisation in Brooklyn, New York City

The picture shows a gold cup from Mycenae. Its special interest for this question is the design: a collection of linked triskelions.

More Info: en.wikipedia.org