Today, the word “Stonehenge” evokes an image of an eerie stone circle standing alone on a windswept plane.

But new digital maps show the prehistoric monument didn’t always look that way. Those 24-foot-tall, 90,000-pound blocks we still find so impressive were actually part of a much larger complex of shrines — including an even-larger “super henge” nearly half a kilometer in diameter.

Using magnetometer readings, ground-penetrating radar surveys and 3D lasar scans, researchers were able to map 17 previously unknown structures that were once neighbors to Stonehenge. (Courtesy of Ludwig Boltzmann Institute for Archeological Prospection and Virtual Archeology)

The maps, which were published Wednesday, were composed using magnetometer measurements, ground-penetrating radar surveys and 3D laser scans by researchers at the Stonehenge Hidden Landscapes Project.

“It was like a large archaeological, geophysical circus come to town,” says project co-leader Vincent Gaffney, an archaeology professor at the University of Birmingham. “We had tractors pulling magnetometers, bikes, everything.”

Driving this machinery across the field surrounding Stonehenge, archaeologists were able to “see through” the ground to detect traces of what once had been. Those traces appear as smudges on the landscape, looking more like microscope images of amoebas than the remains of a giant stone shrine.

Magnetometers like the one being driven here by a member of the Stonehenge Hidden Landscapes Project team are used to “see through” the ground to detect traces of ancient structures that once stood there. – of Geert Verhoeven/LBI for Archaeological Prospection & Virtual Archaeology)

But Gaffney says that the use of multiple technologies let his team “squeeze the majority of information that is available” out of the landscape. And from a series of grainy images, archaeologists were able to reconstruct 17 distinct structures spanning an area the size of 1,250 soccer fields.

Among the new finds are prehistoric pits that form “astronomical alignments,” a timber structure predating Stonehenge in which bodies of the dead were ritually “defleshed” (creepily, the term means exactly what you think it does) and of course, the “super henge” at nearby Durrington Walls, believed to be the largest stone circle in the world.

The discoveries should change the way we think about the area around Stonehenge, Gaffney says. Far from an isolated monument amid a desolate landscape, the maps paint a picture of a bustling complex, complete with ponds, boundary ditches, and smaller sub-chapels clustered around the main stone circle. He envisions the area as part of an ancient procession route — one to which England’s prehistoric residents might have flocked 4,000 years ago.

But largest gathering for which the magnetometers found archaeological evidence is a bit more recent.

“During the free festivals of the 1980s, people dropped bottle caps everywhere,” Gaffney says, laughing. “It’s just a mass of little metal specks with the magnetometers.”

“But how do you see crowds like that in a period when people didn’t drop metal like that? The place could have been heaving and you’d never know,” he added.

If only prehistoric people drank beer.