The British government is moving ahead with a highly controversial plan to build a tunnel under Stonehenge in order to ease traffic around the ancient monument.

At an estimated cost of $2.4 billion dollars, the project will see a major highway expansion that includes the construction of a nearly two-mile-long stretch of road which runs beneath the mysterious site.

Although both the English Heritage Trust, which is the group that oversees Stonehenge, and UNESCO have signed off on the move, the tunnel concept has been met with widespread criticism from a number of quarters.

Find out why the plan is being decried by historians and Stonehenge fans at the Coast to Coast AM website.