The Gravity Bridge - Cambridge

According to local legend, this bridge was originally built without the aid of nails, nuts or bolts. Because the design was so close to perfection, gravity was the only force that held it together .

However, a group of students (with more ego than skill) took the bridge apart and, like the story of Humpty Dumpty, could not put it together again. It had to be rebuilt with nails, nuts and bolts.

There is a lesson here.