A massive structure appears isolated on a flat empty plane. The sides of the structure appear to have straight edges that run down to a large circular 'dot' formation at its base.
NASA says the straight edges may be the result of fractures, related to fractures or a hill that was lifted up by the faulting and its current shape was the result of the surrounding terrain having been eroded down over billions of years.
The same formation as on Mars, has also been found in Kofun in Japan. The Kofun era lasted from AD250 -538.
Interestingly, despite extensive erosion over the structure, the formation exhibits remarkable symmetry.