At an offline vacation, I had little time available and only Ole's hint made me think of "Nazca" and shortly afterwards appeared the dune. Luckly (I'm sure) nobody had the time to look near Nazca, cause it was surprisingly easy!
Now it's time to think about water:
"virtus in media stat"
===== Update =====
I don't know if everyone's on vacation or it's a difficult one ... so, here's 2 pictures, one zoomed in and another zoomed out!
Your goal is to find out the exact location and the (hidro)geology of this place and, if you are the first, you can have the honor of presenting the next WoGE.
No Schott's Rule!
Rules, tips and previous WoGEs are collected by Felix on his blog and a KML file is available with all WoGEs.