Today, the term "caveman" really just means earlier versions of humans, but did they really live in caves? Humans arose in Africa, and eventually migrated to the rest of the world, which was colder and meant they needed shelter. A cave seems like the perfect place to hide from both predators and the elements. But there's a reason we know them as cave men- caves happen to be where we found evidence of early humans.
If caves were not quite as important as was portrayed by the caveman stereotype, why did we find so many traces of palaeolithic life in caves? The answer to that is two-fold: On the one hand, the already existing stereotype of the caveman and early finds in caves naturally oriented more research in caves. It is a selection bias. On the other hand, the conditions for the preservation of fossils in caves are extremely good. Caves not only shelter humans from rain and wind, but also all other kind of things that are left behind in them. Adding to the protection from the weather, many caves accumulate sediment steadily over time burying archaeological traces. They are ideal grounds to conserve a glimpse of the past.
The truth is that people lived in caves and a lot of other places, too, but those other places are not so easy to detect. Read about the many kinds of shelters early humans used and how we manage to find them at Today I Found Out.
(Image credit: Jaroslav A. Polák)