This is a topic better suited for r/AskAnthropology.

As a quick answer, you're making several incorrect assumptions. Modern Homo Sapiens are considered to have appeared 200,000 years ago, whereas Stonhenge is only at most 5,000 years old. That's 195,000 years for migration and technological developments.

First, all this occurred a long time before history began, so this isn't an appropriate subreddit. Second, humans did not evolve from monkeys; there hasn't ever been a single reputable scientist who has claimed that. Third, many of our predecessor species in the Homo genus evolved in Africa and spread out from there and/or moved out of Africa and continued to evolve before Homo sapiens even existed.