The Dingo Fence in Australia is the longest continuous man-made barrier in the world, spanning some 9600 kilometers between New South Wales and Queensland. It was erected to keep dingos (the native wild dogs of Australia) out of sheep-herding areas of southeastern Australia while still preserving their habitat. China’s Great Wall is longer overall, but it’s longest continuous lengths fall far short of the dingo fence.
The jury seems to be out on what is actually the longest man-made structure on Earth. Depending on who you ask, the winner is the Dingo Fence, the Great Wall, or the Trans-Siberian Railroad. But it appears that the longest man-made structure on Earth is probably an underwater cable system. One of these, connecting the UK and Japan spans approximately 28,000 kilometers.
You’ve become quite a fountain of strange factoids