Suppose The Great Wall of China is a series of fortifications made of stone, brick, tamped earth, wood, and other materials, generally built along an east-to-west line across the historical northern borders of China. Several walls were being built as early as the 7th century BC; these, later joined together and made bigger and stronger, are most famous as the Great Wall of China.
Can we infer that "The Great Wall of China is the only man-made structure visible from space."? Yes, no, or maybe?