A week ago, on Wednesday scientists reported the findings of ancient monuments underneath Stonehenge using high-tech mapping. Stonehenge has always intrigued scientists and general public. Situated in Wiltshire, England it’s believed to have between 4000 and 5000 years. And the amazing henge has a stone that reaches 6 metres long. A phenomenal product of human’s hard work and devotion to deities. 
According to National Geographic, “An astonishing complex of ancient monuments, buildings, and barrows has lain hidden and unsuspected beneath the Stonehenge area for thousands of years. Scientists discovered the site using sophisticated techniques to see underground, announcing the finds this week.
Among several cues for the religious underground structure, there were found 17 ritual monuments, that appear to be all Shrine-like structures.
This super project (“Stonehenge Hidden Landscape Project”) took four years to create a high-resolution, 3-D underground map of the landscape surrounding Stonehenge.
The project team, led by researchers from the U.K.’s University of Birmingham and Austria’s Ludwig Boltzmann Institute, mapped the area down to a depth of about ten feet (three meters) using ground-penetrating radar, high-resolution magnetometers, and other state-of-the-art remote-sensing equipment.
In all, nearly 3,000 acres have been excavated virtually, making this the largest and most ambitious project of its kind ever undertaken anywhere in the world.” (adapted text) 
References and further reading.
 – Hidden Monuments Under Stonehenge Revealed by High-Tech Mapping – National Geographic and (audiovisual reference) New digital map reveals stunning hidden archaeology of Stonehenge – University of Birmingham