If you visit this very old city in Britain, you can find the "mathematical bridge," so named because it was supposedly constructed without using nails, but entirely using geometrical principles. Which city?

This legendary wooden footbridge is an iconic landmark in the university city of Cambridge, where it crosses the River Cam at Queens’ College. The popular myth surrounding the bridge is a wonderful piece of local folklore. The story claims that it was designed and constructed by Sir Isaac Newton using only mathematical principles to hold it together, without the need for any nails, bolts, or screws.

While the design is indeed a brilliant piece of engineering, the tale isn't quite accurate. The first version of the bridge was built in 1749, more than two decades after Newton had died. The designer was actually William Etheridge, and his tangent and radial trussing design was a marvel of its time, using short straight timbers to create a strong, arched structure. The "mathematical" part of its name is therefore still very fitting, even without Newton's involvement.

The original bridge did use iron pins at its joints, though they were less obvious than modern fasteners. The current structure is a faithful replica built in 1905, which uses prominent nuts and bolts. This visible hardware likely fueled the second part of the myth: that curious students or fellows once took the bridge apart to see how it worked but couldn't reassemble it without adding bolts.