The correct answer is that the iron support structure was visible
When you build something, the structural points such as pillars are usually not easily discernible to the untrained eye because they fit right there with the remaining walls and things like plaster or bricks. However, his Palace was built out of Glass so the iron supporting structures could easily be seen and it looked great.
A party to an adoption.
Hope this helps
The exact date is unknown but between 550 bc and 539 bc.
Roughly the other 80 percent of the general population.
