The massive monument Stonehenge has captivated people's attention for centuries. Built out of enormous stones on Salisbury Plain, the prehistoric landmark is arguably the most famous ancient construction in England, and it became a UNESCO World Heritage site in 1986.
But Stonehenge is not just a singular, one-off monument — it was built, added to, altered and used for over 1,500 years. And it's also not the only megalithic structure out there; many other ancient cultures have built stone rings that rival Stonehenge.
