A slightly adjacent topic, but I recently reread REH's Red Nails, and I was stuck by how his lost city resembled an abandoned shopping mall. A large low rectangular building, lots of glass in the roof for light, a closed environment, wide east-west and north-south boulevards surrounded by dwellings (some called out as shops) on two levels, a large central atrium under a glass dome, an underground level infested with undead monsters, ornamental turrets and cupolas on the outside, etc.
The problem is, the novella was written 20 years before shopping malls were invented. So I got to thinking what else it resembled, and I thought of the Crystal Palace. I'm pretty sure REH never visited it in London, but it burned down the same year the novella was written, so he may have read descriptions in the newspapers. In addition, there were several copies built in the late 19th century, including a short-lived one in New York. REH couldn't have seen that either. But my research dried up when it came to copies of copies. I suspect there were quite a number built, and furthermore went on to become the architectural inspiration for the original shopping malls.