Stonehenge is known worldwide, but it isn’t the only Neolithic monument to have survived in some form or another to the present day. Nearby Durrington Walls is one of the largest Neolithic monument sites ever found, but it’s nowhere near as well known. That might change though, thanks to a recent study.

The Stonehenge Hidden Landscapes Project uses non-invasive techniques, like ground-penetrating radar, to locate ancient objects without having to excavate, which is time consuming and can permanently damage sites. At Durrington Walls, a huge circular site roughly 500 meters in diameter (about 1,500 feet) and 1.5 kilometers in circumference (nearly a mile), they made some interesting new discoveries.

Durrington Walls was once one of the largest Neolithic settlements in Europe and home to Woodhenge, a monument structure similar to Stonehenge but made–you guessed it–out of wood. The two are thought to be related structures, and Durrington Walls were built about a century after Stonehenge. It seems that the structures buried underneath Durrington Walls are at least as old as Stonehenge itself.

Those structures are standing stones, or at least some of them are, while others have fallen or been pushed over, and still others are only represented by the pits that once held them. Some were as tall as 4.5 meters (about 13.5 feet). These new discoveries point to a much more complicated monument-building culture than previously assumed. Until recently, the builders of Stonehenge and other such monuments have been a mystery, but recent research has told us a lot more about them.

These new discoveries are exciting for several reasons. Obviously they tell us more about the area around Stonehenge, which will allow us to fill in more of the puzzle of who these Neolithic people were. But it also sets a new precedent for archeology and proves that we can explore the ancient world without having to excavate. At least, not without a good idea of what we’ll find.