The final design called for 18,000 pieces of puddle iron and an incredible 2.5 million rivets. Admittedly, that sounds a lot more difficult than the 3D Eiffel Tower puzzle we had as kids.

Lastly, the claw setting connecting the iron hexagon to the rest of the medal is a nod to the Eiffel Tower. The setting is in a shape called “Clous de Paris,” which you’ll find in the rivets dotting ...

The Eiffel Tower is made of wrought iron, which is why its nickname is Iron Lady. Altogether, 18,038 pieces of metal were connected with 2.5 million rivets to construct the tower. The metal frame ...

Eiffel made use of new technology that ... years and used some 18,000 pieces of metal and 2,500,000 rivets. The 300-metre (984-foot) tower it was the tallest structure in the world until overtaken ...