There's a Pot of Gold at the Rainbow's End
One of the most storied rainbow myths is that there's a pot of gold at the end of every one. Not only that, but that the pot of gold is guarded by a tricky leprechaun. The legend goes like this:
Once upon a time, the Vikings lived in Ireland, looting and plundering as they pleased, then burying their ill-gotten treasures all over the countryside. When they eventually departed from the Emerald Isle, they inadvertently left behind some of their booty, which the leprechauns found. Now, the leprechauns knew the Vikings had gotten their treasures through stealing, which was wrong. This bad behavior made the leprechauns mistrust all people, Viking or not. In order to ensure no humans could take what they now considered their gold, the leprechauns reburied it in pots deep underground all over the island. When rainbows appear, they always end at a spot where some leprechaun's pot of gold is buried [source: Mystical Myth].
Here's the catch: Believers who've searched for the legendary pot o' gold always end up stymied, because they can never find the rainbow's end. The reason for that is on the next page.