Hadrian's Wall under siege by thieves wielding metal detectors

A British official has discovered dozens of holes caused by metal detectors at an ancient Roman fortification in the United Kingdom. 

Hadrian's Wall is a UNESCO World Heritage Site near the border of Scotland and England. 

After a recent tip by a member of the public, Historic England inspector Mike Collins visited and discovered the holes around the 1,900-year-old Brunton Turret section. 

He told As It Happens host Carol Off that there have been other instances of illegal metal detecting at the wall in the past couple of years, leading to concerns in his department about a growing trend. 

Here's part of that conversation. 

What are they looking for?

They're looking for metallic objects... that they can sell.

This is not hobby metal detectorists who are really interested in their past, but know that they have to make the proper environmental checks to make sure they're not on protected sites.

• AS IT HAPPENS: Vandals destroy ancient UK rock

This is a very small criminal element who are looking for metal objects that they think they can sell for their own financial gain.

What kind of things could they find around Hadrian's Wall?

There's always a chance of Roman coinage, but also military equipment, and all of the sort of throwaway everyday objects that an army that's in garrison here for more than 300 years discards on a daily basis.

It's that kind of unglamorous stuff that allows us to piece together the story of Hadrian's Wall and increase our understanding.

They're actually digging into it — they're destroying the wall?

It's not the fabric of the wall itself, it's the archeological deposits on either side of that.

Hadrian's Wall is a complex frontier... It's [made up of] all of the archeology, all of the bits and pieces that people have thrown away during 300 years of military occupation in the northeast and northwest of England.

This is a World Heritage site. Describe it and its significance.

It's a Roman frontier that the Emperor Hadrian decreed should be built sometime around AD 122. We know he visited this frontier after what looks like a border war sometime in the AD 119 or 120.

One of his later biographers actually sums it up really well. They said that he was the first to build a wall to separate the Romans from the barbarians.

So it's a frontier wall with a whole series of ditches and banks and earthworks and forts and milecastles and signal towers and camps. It's a really fascinating Roman landscape from a frontier defence point of view. It's not like any of the other frontiers of the Roman Empire. It's making a really powerful architectural statement as well.

We preserve this site, we work on it really hard precisely because people can come and appreciate it and understand it as a common human past.

The police take it very seriously.- Mike Collins

This isn't just nuisance activity [by the metal detectorists]. This is criminal activity, right?

It is. These sites are protected by UK law.

It is a criminal offence to use a metal detector or to dig on them without very specific permissions. These people clearly don't have those and are either very cavalier about not having permission or deliberately seeking to find things that they could sell regardless of what the law says.

The police take it very seriously and if we find information and we can get the individuals who are responsible for this then, yes, they will be subject to potential criminal sanctions.

This transcript has been edited for length and clarity. Written by Katie Geleff and produced by Samantha Lui.