From New York Times:
Stonehenge has captivated generation after generation. Archaeologists have over the years cataloged the rocks, divined meaning from their placement — lined up for midsummer sunrise and midwinter sunset — and studied animal and human bones buried there. They have also long known about the other monuments — burial chambers, a 130-foot-tall mound of chalk known as Silbury Hill and many other circular structures. An aerial survey in 1925 revealed circles of timbers, now called Woodhenge, two miles from Stonehenge.
…
After the end of the grand construction phase of Stonehenge, around 2400 B.C., the monument was altered, but the era of megamonument building was over.
“That’s basically when their world changed,” Dr. Parker Pearson said. New people crossed the channel from Europe, bringing bronze and metalmaking to the stone age culture. “It’s a very interesting shift,” he said. “In a way, Stonehenge is a swan song.”
Something similar befell Gobekli Tepe. A history we know nothing about. Did monuments stand in for writing?
See also: The human mind, the skinny
Evolutionary conundrum: is religion a useful, useless, or harmful adaptation?
and
Imagine a world of religions that naturalism might indeed be able to explain