It has to be Christo and Jean-Claude. No idea when or where, though - except that it seems to be very rural. Imagine living a simple life deep in the country and one morning you pass down your usual lane and see ... this ... "This is art" wouldn't be your first thought!
Or maybe that's not what happened at all.
Surely they are these trees, so beautifully "against the light" -
In a park in Switzerland, 1997-8. See more pix here.