Evolution of Infrastructure:
https://blossom.ditto.pub/06164a51ec63245f015172a2b066e48d78f75d007a678bcbab3bfb4be255bc13.png
https://blossom.ditto.pub/4b8f7c9012e765861c7b8a9622bd17df6fefd9d2f5a2c6cf65...
I wonder how hot that metal will get in the sun. They will learn that maybe marble is the way.