Images: Secrets of Stonehenge unearthed

Now that's a pretty impressive tombstone. New research suggests that Stonehenge was used as a cemetery for more than 500 years, much longer than previously thought. The new findings also show that people used the area as a burial site long before placement of its trademark stones (or sarsen stones) was complete.

The team was led by Mike Parker Pearson, an archaeology professor at the University of Sheffield, with support from the National Geographic Society.

Andrew Chamberlain, a colleague of Parker Pearson's, says burial at Stonehenge was not for commonfolk. He believes Stonehenge was used as a burial site for an elite family, probably ancient royalty.

Archaeologists believe up to 240 people were buried within Stonehenge, all cremated. In its earliest phase, very few people were buried there, but that number grew over time, leading Chamberlain to believe burials became more common as offspring from the family multiplied.

A show exploring the findings will run on the National Geographic Channel Sunday evening.