These mysterious mounds, which can reach heights of seven feet and diameters of thirty feet, have sparked intense scientific debate for over a century, as researchers struggle to identify a definitive cause for their uniform distribution and precise shape.
External link: Exploring the Mystery of Washington’s Mima Mounds video.
Image of a panorama shot of the Mima Mounds in Olympia, WA on a clear winter day from Emxdoom, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons