The Eiffel Tower is six inches taller in summer than winter!

This is largely due to the fact that steel contracts when it’s cold and expands when it’s hot. Because of the fact that the Eiffel Tower was built using steel means the engineers had to account for the shift that would take place in size.

Although it is a small difference, six inches is noticeable to those willing to take the time to measure. It also means that climbing it on foot would be just a little bit harder in the summer.

(Source)