The banner of Melos is derived from a coin of the city, depicting the symbol of the triskeles; the name of this symbol literally means "three legs". It was sometimes used on coins, but more often on shields.
The larger meaning of this symbol is not clear, but an ancient epigram speaks of a triskeles on a shield that is supposed to frighten opponents—the bearer of this shield supposedly ran very fast.
This symbol is still in use today on the Sicilian flag, and that of the Isle of Man.
The eleventh and twelfth labors of Herakles were tacked on at the end, since Eurystheas didn't recognize Herakles killing the Hydra as a labor because Iolaos helped him. Cleaning the stables was also ignored because Herakles was paid, and it was the rivers that did the actual cleaning work.
The eleventh labor required Herakles to steal apples from the garden of the Hesperides, the three nymphs of the evening. The garden was situated in the west of the world, in Northern Africa, and produced golden apples.
There, Herakles tricked Atlas into retrieving the apples for him. Although he proposed to hold up the heavens for a while in Atlas' stead, Herakles tricked the Titan and walked away with the fruit himself.