The mystery of Stonehenge is one that everyone is familiar with and for decades people have stared at the giant circle of stones and wondered who made it and for what purpose?

Scientists from the University of Birmingham and the Ludwig Boltzmann Institute (LBI) are part of the Stonehenge Hidden Landscapes Project and have spent four years studying Stonehenge and the area around it.

The hard work paid off and the team believes they may have found some clues that could help solve the mystery of Stonehenge.

“There are so many questions still to answer”, according to Vince Gaffney, one of the project leads and a University of Birmingham archaeologist. “Despite Stonehenge being the most iconic of all prehistoric monuments and occupying one of the richest archaeological landscapes in the world,” he said in a news release, “much of this landscape in effect remains terra incognita.”

To get a better look at what was hiding below the surface, the team used magnetometers to measure magnetic fields, and radars to survey a portion of the land around Stonehenge.

Researchers find hidden Stonehenge through high-tech imaging: http://t.co/OiEPvukkMc pic.twitter.com/wkWIA7FlF3

— CBS Evening News (@CBSEveningNews) September 10, 2014

“This is among the most important landscapes, and probably the most studied landscape, in the world,” Vince Gaffney told Smithsonian magazine. “The area has been absolutely transformed by this survey. Won’t be the same again.”

The survey found entry and exit spots and two pits, one on the east side and one on the west. The spots form a perfect triangle with Stonehenge delineating when the sun rises and sets.

“Such a pit [the east side one] was much too large for a practical use — for instance, burying trash — because of the labor involved in digging it. In the archaeologists’ minds it could only have ritual implications,” Ed Caesar wrote in Smithsonian. “What’s more, if you drew a straight line between the pit and the heelstone at Stonehenge, it ran directly along the final section of the Avenue, on the path of the sunrise on the summer solstice.”

The team said that they are happy with their survey but added that an underground excavation would be necessary to confirm their findings.