The US's 2,000-year-old mystery mounds

[oldbrownhat]

BBC article here

The Hopewell Ceremonial Earthworks, [was]a large network of hand-constructed hills spread throughout central and southern Ohio...

Built with astonishing mathematical precision, as well as a complex astronomical alignment, these are the largest geometrical earthworks in the world that were not built as fortifications or defensive structures...

...the circumference of The Great Circle "is equal to the perimeter of the perfect square that it was connected to", and that "the area of that perfect square is equal to the area of the [Observatory Circle] that's connected to The Octagon".

... "If you draw a square inside The Octagon by drawing a line from alternate corners of The Octagon, the sides of that square [1,054ft] are equal to the diameter of the circle that it's attached to [1,054ft]."

...that measure of 1054ft, whether halved or doubled, is found in other Indigenous earthworks across the country, and served as a common unit of measure.

"You could put four Roman Colosseums inside just The Octagon," Lepper told me. "Stonehenge would fit within just that small circle now serving as a putting green."

 

[dmn57]

I continue to be fascinated by how ancient civilizations were able to construct monuments with such great precision, many of which from about the same time frame, long before Al Gore invented the internet.

 

[sceva]

Serpent Mound, Southern Ohio

 

[Glynn863]

We have several NA mounds in Alabama. Some are located outside of a town (aptly named) Moundville; there is a state park there that showcases the mounds.

 

[oldbrownhat]

I continue to be fascinated by how ancient civilizations were able to construct monuments with such great precision, many of which from about the same time frame, long before Al Gore invented the internet.

LOL. And without thedolites, GPS or iPhones. Real Erich van Däniken stuff

@sceva: They mention the Serpent Mound in Peebles in the article, too. Not, apparently from the Hopewell culture, but fascinating. Its alignment is solar, which is more common. But the Hopewell earthworks are aligned with the lunar cycle. They must have been very patient.

"...while the Sun can be tracked over a year, a complete lunar cycle takes 18.6 years. Even so, the lunar cycle proved to correspond to the position of the Observatory Mound at The Observatory Circle. There, one can watch the Moon rise over the exact centre of The Octagon in the distance every 18.6 years... "