It was man who blew it up, who else. Read The Last Day of Creation http://en.wikipedia.org/wiki/The_Last_Day_of_Creation for the full story.

why built such a thing? because it doesn't matter who you are ... blahblahblah ... everybody asks why did they build it? so why did they built it? because it doesn't matter who you are ... infinite recursion

do you think, future archeologists will catch this???