A sample image....A damaged or ruined pyramid..
Look closely........
http://marsesa.9f.com/slide_shows/Cydonia_Images/fig846.jpg
The Cydonia region has many interesting and quirky formations which is probably why Hoagland and his imitators fixate on it. Your "ruined pyramid," other pyramid-like formations, and even the infamous "Skull" are a combination of natural formations with some "pareidolia" (which is basically a trait we all have for looking for patterns in things) sprinkled in. Many people are unaware how nature can fashion many unusual formations all on it's own, and not just pyramidal shapes. Check out
this "face" courtesy of Google Earth.
The Mars Express Cydonia images are touched on in
this item from the ESA along with why, even though they aren't artificial, these formations are still of interest in a geological sense.