In July 2015, this feature on Mars was found by researcher David Gannett and attracted wide media interest due to what appeared to be its remarkable 'dome' shape.
Much less reported was the fact that a year later, the Opportunity Rover got much closer to it, taking pictures from a different angle which showed quite a different character. The dome shape disappears, but a rounded, curved form remains.
So, do we have just a pile of rocks here, or something far more interesting? Given its strange shape, it remains odd that a decision was not made to get an even closer look.
For a full report, more images and GIF movie, go to: https://www.secretmars.com/maa023-dome-feature.