"Earth Piled Up" - earthen mounds made by people

The largest prehistoric mound in the USA- [~ 700,000 cubic meters)
Monks Mound, ca. 900-1200 CE

(not by aliens or Atlanteans, by the way)

 

Photographed when it was newish, in October, and I think it's already gone.

 

Anthills from hell. (Not our regular nasty fire ants)

 

Spoil mound from gravel quarry, circa 2010.

 

What remains of the Teton Dam, which breached while being filled for the first time in 1976. The ensuing flood killed eleven people and caused billions of dollars in damages.

 

Thanks, Glenn, I’ve just read about the incident on Wikipedia. Apparently, the flood crashed into a timber yard and sent hundreds of logs crashing into a fuel dump which then exploded. Scary stuff.

 

Anyhoo, I came across this on my morning hobble and thought of a more controlled flooding. You can just about see the sea water being pumped through the centre mound