Worldbuilding Challenge Day 22 - Fantastical Water

What prominent fantastical body of water are there?

Hidden deep in the jungles around Vence are the Floating Waterfalls of Fortune. It is said whoever can find the waterfall, and swim in its waters without being pulled over the edge, will obtain wealth beyond measure. Many have tried to find the waterfalls, yet many are the primal dangers that lurk in the skies over this unclaimed wilderness.