http://www.unmuseum.org/hangg.htm
http://www.angelfire.com/ny/anghockey/hanginggardens.html
http://www.cleveleys.co.uk/wonders/gardensofbabylon.htm
<sarcasm>
WARNING: the above sites contain artists drawings of 100% REAL nude plants! Thats right nude plants! If you are not 18 years or older, leave now! You'll look at these pictures and say "wow look at the leaves on that one!" And "man those Babylonians really knew how to make some hot looking gardens!" and "Man I'd call THAT a wonder of the world!"
</sarcasm>

I dunno, maybe I use a different Google than you do, but those are the first 3 sites I got back, doesn't look like porn/nudity/sex to me.