5. The Most Precious Material
The Washington Monument, one of the most iconic landmarks in the United States, boasts a unique feature at its top: a cap made of aluminum. At the time, aluminum was an exceedingly rare and precious metal, so valuable, in fact, that it was priced higher than gold.
This was due to the complexity and costliness of its extraction process, which made aluminum a symbol of wealth and status. The decision to cap the monument with aluminum was not only a technical achievement but also a statement of the monument’s significance and the nation’s aspirations.