The sign says, "Do Not Go Beyond This Point". Sage advise I would say . . .
Fence? It may be invisible, but it is indeed there!

This photo was taken from a Yashica ELECTRO 35CC rangefinder film camera with a COLOR-YASHINON DX 1:1.8 f=35mm lens, the Kodak 135 transparency scanned by an HP Scanjet G4050 and digitally restore using Photoshop.