A peer has compared an ancient monument to the pyramids in a row over the government's right to roam laws.
Silbury Hill dates back more than 4,000 years to the Neolithic period
Lord Avebury says he is "stunned" the Countryside Agency's wants to label Silbury Hill in Wiltshire as "unimproved chalk grassland".
The move could lead to ramblers having free access to the hill, which opponents fear may cause damage.
However, the agency says it took the decision because the 4,700-year-old hill is a "man-made structure".
Lord Avebury spoke at the public inquiry into the wording of the Countryside and Rights of
Way Act draft legislation.
The act has already sparked one high-profile spat in Wiltshire with pop star Madonna keen to protect her privacy and estate from walkers and inquisitive sightseers.
On Monday Lord Avebury told the hearing, at Hungerford, Berkshire, the hill was
"comparable with the ancient Pyramids of Egypt or the Great Pyramids of
Silbury Hill, near Avebury, is thought to date back nearly 5,000 years to the Neolithic period.
Archaeologists from English Heritage began investigating the hill four years ago after a hole appeared in the top, prompting fears it could collapse.