Was Atlantis a real city? If not, why have so many people gone looking for it? In part two of our series on modern myths and legends, we’re searching for lost cities.

We’ll trace the origins of El Dorado, and head to the ruins of an actual lost city in Egypt. We'll find out how mangrove trees could help prevent cities from being lost to climate change, and Sanden and Marc are back with another edition of Hoax Hunters. Plus, a Moment of Um about how tattoos stay put.

Today’s episode is sponsored by Quip (getquip.com/brains), KiwiCo (kiwico.com/brains), American Dental Association (ADA.org/brains) and Stitch Fix Kids (stitchfix.com/kids/brains). You can support Brains On at brainson.org/donate and get a bonus Mystery Sound Extravaganza episode this January!