The gammadion, or rather the tetra-gammadion, is an ancient symbol also known as swastika. The name gammadion comes from the fact that it can be seen as being made up of four Greek gamma (Γ) letters. Ancient Greek priestesses would tattoo the symbol, along with the tetraskelion, on their bodies. Ancient Greek architectural designs are replete with the interlinking symbol.
In alchemy, the gammadion was used to symbolise the four cardinal corners of the world and the guardianship of this world.