There is so much science fiction writing from the golden age and beyond, up to the 60s and 70s, which prominently features Martians and Martian cities. Mars having alien life was a massive source of speculation among the public at that time. While the stories are still great, reading them today I can't help but go "nah we've been to Mars, there's nothing there".

Makes me think about how soon sci-fi written today will get similarly outdated.