It's a 5000 year old structure that pre-dates the Indo-European settlement of the United Kingdom by centuries, surrounded by hundreds of burial mounds of a people who no longer exist.
It's aligned with the sun in such a way that it suggests the pre-European people of 3000BC were engaging in astronomy and had the ability to predict celestial phenomena decades in advance despite not having writing.
Some of the stones were sourced from ~150 miles away, which, considering they weigh ~5 tons, is a hell of a feat in 3000BC.