Metropolis, at least initially, was inspired by Toronto and Cleveland.
Superman's creators (Jerry Siegel & Joe Shuster) took inspiration from their personal lives. Siegel was a Cleveland native, and Shuster was originally from Toronto (his family moved to Cleveland when he was 10).
The Daily Planet newspaper was originally called "The Daily Star" in the comics after Toronto's major newspaper, the Toronto Star (formerly the Toronto Daily Star).
These are the words of Superman's creators:
"Actually, the Planet and the architecture of Metropolis were based on Shuster’s childhood memories of the skyline of Toronto, where his family lived until 1924, when he was 10. “Cleveland was not nearly as metropolitan as Toronto was, and it was not as big or as beautiful,” Shuster told The Toronto Star in 1992. “Whatever buildings I saw in Toronto remained in my mind and came out in the form of Metropolis.”
The Cleveland skyscraper that really inspired Siegel and Shuster was the Terminal Tower, 708 feet tall and brand-new in the early 1930s.
“We would walk all the way downtown because we could not afford streetcar fares,” Siegel recalled in a 1988 letter to Mayor George Voinovich. “We looked up at Cleveland’s Terminal Tower and visualized a costumed figure (who had not yet seen print) whizzing through the sky around it and then alighting atop it. On a secret, tremendously important mission, no doubt.”
