London, June 22 : Archaeologists have discovered a ring of prehistoric shafts, dug thousands of years ago near the ancient monument of Stonehenge in England, it was reported on Monday. Fieldwork has revealed evidence of a 2 km wide circle of large shafts measuring more than 10 metres in diameter and 5 metres in depth, reports the BBC. They surround the ancient settlement of Durrington Walls, 3 km from Stonehenge. Tests suggest the ground works are Neolithic and were excavated more than 4,500 years ago. Experts believe the 20 or more shafts may have served as a boundary to a sacred area connected to the henge. A team of academics from the universities of St Andrews, Birmingham, Warwick, Glasgow and the University of Wales Trinity Saint David worked on the project. "Remote sensing and careful sampling is giving us an insight to the past that shows an even more complex society than we could ever imagine," the BBC quoted Richard Bates, from St Andrews' School of Earth and Environmental Sciences, as saying. "Clearly sophisticated practices demonstrate that the people were so in tune with natural events to an extent that we can barely conceive in the modern world." Nick Snashall, National Trust archaeologist for the Stonehenge World Heritage Site, hailed the "astonishing discovery". The announcement of the discovery comes after the Summer Solstice, which took place online this year as the annual gathering at Stonehenge was cancelled due to the COVID-19 pandemic. /IANS