The Tartarus Sunspot is a sunspot that rotates in Earth's direction every few thousand years.
At some unknown point in Earth's history, a race of super-ancient beings discovered the Tartarus Sunspot, and through their research learned that roughly every 4,000 to 4,500 years it would align with the Earth, causing the polar ice caps to melt and cause sea levels to rise.
In response, the Super-Ancients constructed a Golden Capstone with a crystal peak which could absorb the excess heat, keeping global temperatures the same. They were somehow also able to make it that should a ritual of power be performed, then the nation who had the dirt of their homeland deposited beneath the Capstone during the Rotation event would receive 1,000 years of absolute power.
The Super-Ancients knew that even after they were gone from the Earth (by extinction, or otherwise departing the planet), there may yet be intelligent life, and decided to make the use of the Capstone to absorb the energy of the sunspot the first of five trials, which would allow them to determine if a new sentient species had arisen and were worthy of existing.
After the Super-Ancients were gone, the Tartarus Sunspot continued to afflict the Earth every few thousand years, with polar ice caps melting and causing sea levels to rise with each rotation.
However, a few years prior to 2570 BC, the Old Kingdom of Egypt were able to find and figure out how to use the Capstone to avert the Tartarus Rotation. They began constructing a pyramid and left the uppermost part unfinished so that the Golden Capstone could be set in place. A few years after the Great Pyramid was completed, the next Tartarus Rotation occurred, but thanks to the Capstone, the rise and temperatures and major flooding that had besieged Earth for several of its previous rotations were prevented.
- The Tartarus Sunspot is named after the ancient Greek word for hell.