LONDON, June 20 (Xinhua) -- Hadrian's Wall, built by Roman conquerors of Britain, is being threatened by treasure hunters using metal detectors, it was revealed Wednesday.

Cultural watchdogs, Historic England, said a surge in illegal metal detecting has made more than 50 holes having been found at Brunton Turret along Hadrian's Wall.

Archaeologists from Historic England have called on visitors to Hadrian's Wall to report illegal metal detecting as criminals are targeting the spectacular 1,900 year old World Heritage site.

The wall stretches for 117 kilometers between Wallsend in North Tyneside and Bowness on Solway in Cumbria and has about 160 scheduled monuments, which include Roman camps, forts and signal stations.

More than 50 holes made by nighthawks, the term for illegal metal detectors, have been discovered at the Brunton Turret section of Hadrian's Wall.

The turret and the well-preserved section of Hadrian's Wall next to it were built by the men of the Twentieth Legion of the Roman Army.

The remains above ground are surrounded by further buried archaeological remains from the Roman frontier, and it is these remains that are very vulnerable to damage from nighthawks, said Historic England.

Mike Collins, Historic England's Inspector of Ancient Monuments at Hadrian's Wall, said: "The small number of people who steal artefacts and damage ancient sites are breaking the law and robbing us all of the knowledge and understanding that objects from the past can give us.

"These nighthawks are committing a criminal offence and we'd like everyone's help to ensure they are caught. Together we can protect the precious shared legacy that our archaeological sites hold."

Historic England said there has been a spate of "nighthawking" incidents at Roman Wall sites at Corbridge, Housesteads and Steel Rigg.

"These three sites, along with the rest of the Hadrian's Wall frontier, are nationally important and are protected as Scheduled Monuments. It is a criminal offence to use a metal detector in such places without proper authorisation," added Historic England.

Mark Harrison, Head of Heritage Crime and Policing Advice for Historic England said: "Illegal metal detecting is not a victimless crime. We may never see or fully understand the objects taken or damaged because they have been removed from their original sites with no care or record as to their history or context."

The latest incident at Brunton Turrett is now being investigated by Historic England and Northumbria Police.