The people who built Stonehenge came from the Mediterranean, according to a DNA research. Researchers took DNA samples of ancient Britons as well as modern inhabitants of the UK and discovered that their ancestors all came from regions in Anatolia, which is in modern day Turkey from across the Mediterranean.
Based on the research, scientists believe that there was indeed a population of hunter gatherers living in the British isles at the time people came from the East. However, the populations were so small, they were entirely replaced.
According to the data, these neolithic people brought farming, from where it began in Anatolia, moved through Spain and Portugal (Iberia) before crossing over the channel to Britain. They began arriving in 4,000 BC.
This would mean that these farmers nearly immediately started building megalithic structures to track the solar year. Although Stonehenge was most likely not constructed until around 3,000 BC, there are earlier signs of megalithic architecture in the region beginning earlier.
It is believed the earliest people could have come via Wales. Although there is no genetic trace of the earlier peoples living in the region, except for a tiny part of Scotland, scientists think the populations were so small, the DNA was simply lost in the ocean of genetic diversity pouring into the region.