The mysteries of Stonehenge are revealed sometimes by unusual methods—forgetting to water its grass or whacking its stones with quartz. In this case, it just took four years of staring at the ground. A new underground survey reveals a vast complex of unknown Neolithic monuments near Stonehenge, including a huge stone "super henge." 
 
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 The Stonehenge Hidden Landscape Project has spent the past four years sweeping the area around Stonehenge with ground-penetrating radar and GPS-guided magnetometers. Without ever picking up a shovel, archeologists have mapped the ground up to two miles deep in extraordinary detail. It's staring at the ground—but with high-tech tools. 
 
 Surveying the ground around Stonehenge. Credit: Stonehenge Hidden Landscapes Project 
 
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 Among the hundreds of features that were mapped are 17 newly discovered Neolithic monuments, all dating to the same period as Stonehenge about 5,000 years ago. These pits and ditches, marked by post holes, often seem to be astronomically important. 
 
 There is the Cursus, for instance, a rectangular space which is under two miles long and 300 feet wide. Two pits inside the Cursus appears to be aligned with the rising and setting sun on the summer solstice when seen from the Stonehenge's heel stone. Taken together, the monuments suggest Stonehenge is the most obvious remainder of a large complex of structures with ritual importance. 
 
 The survey also revealed surprising facts about known structures, like the Durrington Walls, a dirt bank that encircles a circumference of a mile. Underneath one section of the dirt, archeologists found more than 50 huge stones, each 10 feet long, forming a "super henge." "That's a big prehistoric monument which we never knew anything about," the co-director of the investigation, Professor Vince Gaffney, told Nature. The structure, which faces the River Avon, could have a ritual connection with the water. 
 
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 The BBC is a devoting a two-part TV series to the Stonehenge Hidden Landscape Project, which will air on the Smithsonian Channel in the U.S. beginning September 21. For the more immediately curious, Smithsonian Magazine also visited the scene of the survey, where tractors pushed ground-penetrating radars "like high-powered lawn mowers" and all-terrain vehicles "dragged the magnetometer sensors on long strings." This is what modern archeology looks like: no shovels, lots of gizmos, and big data. [Financial Times, The Independent, Nature] 
 
 Top image: donsimon/shutterstock ||||| Researchers find hidden remains of massive Neolithic stone monument, thought to have been hauled into position more than 4,500 years ago 
 
 Archaeologists have discovered the remains of a massive stone monument buried under a thick, grassy bank only two miles from Stonehenge. 
 
 The hidden arrangement of up to 90 huge standing stones formed part of a C-shaped Neolithic arena that bordered a dry valley and faced directly towards the river Avon. 
 
 
 
 Researchers used ground-penetrating radar to image about 30 intact stones measuring up to 4.5m tall. The fragments of 60 more buried stones, or the massive foundation pits in which they stood, reveal the full extent of the monument. 
 
 
 
 Facebook Twitter Pinterest Vince Gaffney discusses Durrington Walls on BBC Radio 4’s Today programme 
 
 “What we are starting to see is the largest surviving stone monument, preserved underneath a bank, that has ever been discovered in Britain and possibly in Europe,” said Vince Gaffney, an archaeologist at Bradford University who leads the Stonehenge Hidden Landscape project. “This is archaeology on steroids.” 
 
 
 
 Facebook Twitter Pinterest A motorised magnetometer system is used to survey the land around Stonehenge. Photograph: Geert Verhoeven/Stonehenge Hidden Landscape/PA 
 
 The stones are thought to have been hauled into position more than 4,500 years ago to form the southern edge of a ritual arena centred on a natural depression. The stones appear to have joined up with a chalk ridge that had been cut into to accentuate the natural border. 
 
 
 
 “We presume it to be a ritual arena of some sort,” said Gaffney, whose team has mapped the terrain and subsurface features around Stonehenge with a rich suite of instruments. He will describe the latest findings from the site on Monday at the British Science festival in Bradford. 
 
 
 
 Facebook Twitter Pinterest Click to see what the huge standing stones would have looked like when they were built more than 4,500 years ago 
 
 Images of the buried stones show them lying down, but Gaffney believes they originally stood upright and were pushed over when the site was redeveloped by Neolithic builders. The recumbent stones became lost beneath a huge bank and were incorporated as a somewhat clumsy linear southern border to the otherwise circular “superhenge” known as Durrington Walls. “This is a new element of how the Stonehenge landscape was transformed.” 
 
 
 
 A mile in circumference, Durrington Walls is one of the largest known henge monuments. It is surrounded by a ditch and a 40m-wide, 1m-tall outer bank. The henge surrounds smaller enclosures and timber circles from a later settlement. 
 
 
 
 The Stonehenge Hidden Landscape project has transformed how archaeologists view the ancient site, which sprawls over 4 sq miles of Salisbury Plain in Wiltshire. The main monument stands at the heart of a landscape rich with burial grounds, pits and chapels. Last year, researchers found the remains of 17 new chapels and hundreds of other archaeological features scattered across the site. 
 
 
 
 Two huge pits have been discovered in a two mile-long monument called the Cursus that lies to the north of Stonehenge. The pits seem to form an astronomical arrangement: on midsummer’s day, the eastern pit’s alignment with the rising sun and the western pit’s alignment with the setting sun intersect where Stonehenge was built 400 years later. 
 
 
 
 The rise and fall of the newly discovered monument at Durrington Walls suggests that buildings were modified and recycled since the first stones were laid around 3100BC. A large timber building encased in chalk is thought to have been a house of the dead where defleshing was performed as a burial ritual. 
 
 
 
 Facebook Twitter Pinterest The location of newly discovered monuments around Stonehenge. Photograph: Geert Verhoeven/Birmingham University/PA 
 
 Paul Garwood, an archaeologist and lead historian on the project at the University of Birmingham, said the the new discoveries at Durrington Walls changed fundamentally how researchers understood Stonehenge and the world around it. “Everything written previously about the Stonehenge landscape and the ancient monuments within it will need to be rewritten,” he said. 
 
 
 
 Nick Snashall, a National Trust archaeologist for the Avebury and Stonehenge world heritage site, said: “These latest results have produced tantalising evidence of what lies beneath the ancient earthworks at Durrington Walls. The presence of what appear to be stones, surrounding the site of one of the largest Neolithic settlements in Europe, adds a whole new chapter to the Stonehenge story.” ||||| Ludwig Boltzmann Institute 
 
 Every summer solstice, tens of thousands of people throng to Stonehenge, creating a festival-like atmosphere at the 4,400-year-old stone monument. For the 2015 solstice, they will have a bit more room to spread out. A just-completed four-year project to map the vicinity of Stonehenge reveals a sprawling complex that includes 17 newly discovered monuments and signs of a 1.5-kilometre-around ‘super henge’. 
 
 The digital map — made from high-resolution radar and magnetic and laser scans that accumulated several terabytes of data — shatters the picture of Stonehenge as a desolate and exclusive site that was visited by few, says Vincent Gaffney, an archaeologist at the University of Birmingham, UK, who co-led the effort. 
 
 Take the cursus, a 3-kilometre-long, 100-metre-wide ditch north of Stonehenge that was thought to act as barrier. The team’s mapping uncovered gaps in the cursus leading to Stonehenge, as well as several large pits, one of which would have been perfectly aligned with the setting solstice Sun. New magnetic and radar surveys of the Durrington Walls (which had been excavated before) uncovered more than 60 now-buried holes in which stones would have sat, and a few stones still buried. 
 
 “They look as they may have been pushed over. That’s a big prehistoric monument which we never knew anything about,” says Gaffney, who calls the structure a ‘super henge.’ His team will discuss the work at the British Science Festival this week, and they plan to present it to the institutions that manage the site. “I’m sure it will guide future excavations,” Gaffney says. ||||| Last year archeologists discovered "Superhenge", or what was thought to be around 90 stone monolithic structures buried a meter below ground, just a few kilometers northeast of the Stonehenge in Wiltshire, England. The blocks were over 4,500 years old. 
 
 It turns out, however, that the circular Superhenge was actually made of timber, and that it was hurriedly taken down. The research team that made this discovery hypothesize that the Superhenge might have been constructed and deconstructed during a tumultuous time, rife with political or religious conflict. 
 
 Geophysical survey techniques allowed scientists to first discover Superhenge and conclude that each monolith was organized in a circle with a diameter of about 500 meters. They did not actually, however, excavate the site. 
 
 Now a recent excavation of the Superhenge site has revealed that the standing monoliths were neither standing, nor stone, nor even monolithic. These structures are actually giant pits that once contained wooden posts. 
 
 "The response from the radar was so good that the team thought they were dealing with a whole series of stones lying on their side, buried beneath the bank of this ancient earthwork," Nick Snashall, UK National Trust archeologist, told the BBC. 
 
 So far two of the pits have been excavated, officially disproving the stone theory. "What we've discovered are that there are two enormous pits for timber posts. They have got ramps at the sides to lower posts into," said Snashall. "They did contain timbers which have been vertically lifted out and removed at some stage. The top was then filled in with chalk rubble and then the giant henge bank was raised over the top." 
 
 It's not clear, however, why the original builders of the Superhenge took out the wooden posts and left the ditch that scientists discovered today. It also seems as if the circle of wooden posts was never actually completed. Instead, when the posts were removed, the ditches were filled with chalk. At the bottom of one of the holes, archeologists also found a spade tool, made from a cow's shoulder blade. 
 
 The story of the Superhenge is not yet clear, but some theorize that the site reflects Britain's tumult as tribal society shifted from the Neolithic period to the Bronze Age, and the change in religious practice around that time, too.
– Some observers believe Stonehenge was once a full circle of enormous stones—and now there seems to be proof there are even more Neolithic monuments underneath it. A lot of them: Radar mapping that's peeked as far as 2 miles beneath the surface has uncovered an elaborate subterranean network of 17 monuments, plus evidence of more than 50 big stones that are around the same age as the above-ground versions, Gizmodo reports. The stones, which are being called a "super henge," are part of the already-excavated Durrington Walls dirt bank and are "a big prehistoric monument which we never knew anything about," one of the project's archaeologists tells Nature. The discovery was made by researchers with the Stonehenge Hidden Landscape Project, which has been using geophysical info to "create a highly detailed archaeological map of the 'invisible' landscape." This includes the "Cursus," a 2-mile-long pit with sections that line up with the summer solstice sunrise and sunset, and the 1-mile-round "super henge," riddled with holes where 10-foot-long stones once sat—some are still there. Researchers still don't know what the place was, with Smithsonian Magazine suggesting everything from a temple or parliament to a graveyard. (Read about a Stonehenge mystery that may have finally been solved.)