TIP: DON'T SETTLE FOR PHOTOS: SEE IT IN PERSON!
I'm not sure. The development of the first atomic bomb may have taken more resources than the building of the Great Wall of China. Maybe nobody knows. But certainly the Great Wall would be secondin resources used, and probably second in the waste of such resources, too.
In an attempt to keep keep the barbarians out of China, I think it was Shr Wang Di, the first emporer of a United China, that began the Great Wal around 4,000 years agol. It was extended, deteriorated, repaired, further extended, and even though built so long ago, remains the only man-made structure that can be seen from space.
Pictures of it are beautiful--perhaps more beautiful than the real structure. But pictures will never give you the awe of actually standing upon a part of the recently repaired wall and seing it winding like a snake through the northern China mountains.
Seeing both the recently repaired portions near Beijing, and portions deteriorated almost to the point of non-existance, (which is most of it), gives one a feeling of smallness that people so long ago could have built such a structure; and a feeling of pride to be one of the same species that built it.
Number one or number two in resources used for a single project, a little study will reveal that it never fulfilled it's purpose. Chinese traitors let barbarians through the wall; skilled invaders simply road through it like it was straw. (Interestingly, the competing project for most resources spent, the first Atomic Bomb, also fairled in it's greater purpose--to prevent war--and almost brought the world as we know it to an end.)
It's cold on the Great Wall in the winter, and hot in summer. So what. You'll forget that. But you'll never forget that you stood on perhaps the greatest and largest lasting work of our speceis. TIP: DON'T MISS IT!
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC