Comment: There are far more provocative "structures" on Mars than that...

"Sphinx" on Mars http://www.enterprisemission.com/Path-sphinx.html
"Glass Tunnels" or transportation tubes on Mars http://www.enterprisemission.com/images/arthur.jpg

These are NASA photographs, but the markups are Richard C. Hoagland and Mike Bara. Hoagland was Walter Cronkite's Science Editor at CBS News and Mike Bara is his associate.

Here is what the late Arthur C. Clarke ("2001: A Space Odyssey" said to former Astronaut Buzz Aldrin.

"I'm fairly convinced that we have discovered life on Mars," Clarke told SPACE.com Sunday as Buzz Aldrin listened. "There are some incredible photographs from [the Jet Propulsion Laboratory], which to me are pretty convincing proof of the existence of large forms of life on Mars! Have a look at them. I don't see any other interpretation."

http://www.enterprisemission.com/sir.htm