Once part of a large culture of stone circles, Stonehenge—built around 3000 B.C. and developed over the next 1,500 years—is the most famous. The remains of a once-wealthy and evidently learned tribal community, it reflects the apparently disparate subjects of archaeology, astronomy, metrology, sacred geometry, and even shamanism. How were eclipses predicted at Stonehenge? Why were some stones brought all the way from Wales? What is the secret geometry of seven eights? These and many other questions are answered—and Stonehenge's secrets revealed—in this fascinating small book.