Conspiracy theorists claim to have found evidence of 'ancient walled cities' on Mars in their latest bizarre theory. 

The United Family of Anomaly Hunters, a group of UFO hunters, presented the evidence in a YouTube video.

The video shows a series of aerial Nasa pictures of Elysium Planitia is a plain near the Martian equator.

The images show a number of aerial views, some of which look like eroded domes that could be surrounded by virtually circular rings.

The ring and cone structures were spotted on Elysium Planitia, a plain near the Martian equator.

To read more and view the video, click here.