Stonehenge, located in Wiltshire, England, was constructed in several stages over a long period. The first major construction at the site, known as Stonehenge I, was a circular earthwork enclosure built around 3000 BC during the late Neolithic period.
The iconic stone circles that are visible today, known as Stonehenge III, were erected in the late Neolithic to early Bronze Age, roughly between 2500 BC to 2000 BC. The larger sarsen stones were erected around 2500 BC, while the smaller “bluestones” may have been placed slightly later.
There were additional modifications and rearrangements of the stones in subsequent centuries, with the final changes made around 1500 BC.
So, the oldest parts of Stonehenge are over 5000 years old, while the stone circles themselves are around 4500 to 4000 years old as of this writing.