I'll add three more threes (=nine) of threes for you... I have been spending a lot of time on the Perseus myth lately. It is interesting that it takes place in three regions (Argos, Seriphos, and Ethiopia); it is Hermes (the "thrice-greatest") and Athena (the "thrice born") who support him in his questing; that together with Perseus they make three children of Zeus; that he encounters three old women, three nymphs, three Gorgons; that he receives three magic items from the nymphs; and that, at the end, Perseus restores balance to the warring Argolid (Argos is the west, Tiruns in the east) by building and fortifying a third city (Mukenai).

I've spent a lot of time on fours in the past (Fire/Air/Water/Earth, Osiris/Set/Isis/Nephthys, the One/the Intellect/Soul/Nature, etc.) but I'm starting to have to push myself to think in threes... one of these days I'm going to have to dig up and translate the fragments that we still have of Pythagoras's number-lore.