Caves of Steel: Life Lived Indoors Forever

In Isaac Asimov's Caves of Steel (1953), Elijah Bailey and his robot partner R. Daneel Olivaw pursue a murder mystery in future New York, an enormous domed city of 20 million people. Citizens are so habituated to living indoors that they are fearful of going outside and have lost the desire to explore other worlds. Links to the story; a different cover is shown above.