Gwynedd Heritage Quarry Arson Probe Underway, Wales 2026

Key Points

• The North Wales Police are currently looking into allegations of arsons, criminal damage, and anti-social behavior at Dinorwig Quarry.
• Dinorwig Quarry is a component of the landscape of the UNESCO World Heritage Site within Gwynedd.
• The police have stated that the site consists of buildings and monuments of national and international significance.
• The damage includes windows that have been broken, vandalism at the buildings, historic slate buildings that have been damaged, and the aftermath of the fire.
• They said that damaging historic buildings may mean that historic features may be lost permanently.
• Security through CCTV and increased security are going to be put in place with the help of landowners and agencies.
• The policing plan will comprise high-visibility and covert patrols for the prevention of crime.
• The North Wales Police has appealed for witnesses who can provide information on those committing the crimes.
• If a crime is in progress or you are under any imminent threat, contact 999 immediately.

Wales (Wales Times) September 2, 2026 – It is investigating repeated incidents of criminal damage, arson and anti-social behaviour at Dinorwig Quarry, a protected historic site forming part of the UNESCO World Heritage Site landscape in North Wales.

The police investigation follows concerns about damage to buildings, historic slate structures and other features at the quarry. Officers from the North uk/police/">Wales Police Rural Crime Team said the incidents were causing lasting harm to the site and warned that those responsible could face robust action.

Dinorwig Quarry is located in Gwynedd and is connected to the area’s industrial and cultural history. According to the police statement reported by the Daily Post, the site includes listed buildings and scheduled monuments, meaning it receives additional protection under the law.

The Rural Crime Team said the damage was not limited to one type of incident. Photographs released alongside the police appeal showed broken windows, damage to historic slate structures, vandalism to buildings and the aftermath of fire-related incidents.

Why is the site protected?

Dinorwig Quarry is part of a landscape recognised for its historical importance. The police said its heritage status means that the quarry is more than an abandoned or disused industrial location. It is also a protected heritage asset linked to the history of slate production and the development of the surrounding area.

A statement from the North Wales Police Rural Crime Team said Dinorwig Quarry was “not only an important part of the area’s industrial and cultural history” but also part of the UNESCO World Heritage Site landscape.

The statement added that the site contained listed buildings and scheduled monuments, describing it as a protected heritage asset of “national and international significance”.

The police said historic structures and monuments could suffer permanent damage when they were vandalised, damaged or affected by fire. Unlike modern buildings, many historic features cannot easily be replaced or restored to their original condition.

The force warned that the loss of architectural, industrial or archaeological features could permanently reduce the site’s heritage value. It also said the legal protection given to the quarry meant people found responsible for offences there could expect to be dealt with robustly.

What damage has been reported?

The incidents described by North Wales Police include criminal damage, anti-social behaviour and arson. The force did not identify individual suspects or announce arrests in the statement reported by the Daily Post.

Images released as part of the appeal showed several forms of damage. These included:

• Broken windows.
• Damage to historic slate structures.
• Vandalism affecting buildings.
• Fire-related damage and the remains of incidents involving fire.

The police did not state the total financial cost of the damage. They also did not provide details of the precise dates of each incident, the number of separate offences or whether any particular building had been targeted repeatedly.

The Rural Crime Team said the incidents had taken place over recent months. The wording of the statement indicated that officers were dealing with a series of reported events rather than one isolated act of vandalism.

What action are police taking?

North Wales Police said it would work with landowners and partner agencies to improve security at Dinorwig Quarry. The measures are intended both to discourage further offences and to help identify those responsible.

The planned measures include CCTV, regular high-visibility patrols and covert patrols. High-visibility patrols allow officers to be seen in the area and can provide a visible deterrent. Covert patrols are intended to support the detection of people involved in offending without revealing the full details of police activity.

The force said additional security arrangements would be introduced because of the nature of the site and the repeated reports of damage.

The approach will involve cooperation between the Rural Crime Team, landowners and other agencies. The police did not provide a timetable for the installation of CCTV or say how many cameras would be deployed.

The statement also did not say whether access to any part of the quarry would be restricted. Any changes to access would depend on the landowners, heritage authorities and other relevant organisations involved in protecting the site.

What did North Wales Police say?

In the statement reported by the Daily Post, the North Wales Police Rural Crime Team said: “Over recent months, there have been repeated incidents of criminal damage, anti-social behaviour and arson at Dinorwig Quarry.”

The team said the location was a protected heritage asset containing listed buildings and scheduled monuments. It warned that damage to historic structures and monuments could have a lasting impact and result in the permanent loss of important heritage features.

The police statement said the quarry was afforded “additional protection in law” because of its heritage status. It added that anyone found responsible for committing offences there could expect to be dealt with robustly.

The force also said it would work closely with landowners and partner agencies to protect the area. The planned response would include CCTV, regular visible patrols and covert patrols aimed at deterring and detecting offending.

Police described the released photographs as showing only “some of the damage” caused at the site. The images were intended to demonstrate the nature of the reported incidents and encourage people with information to contact investigators.

How can witnesses report information?

North Wales Police appealed to anyone who had witnessed damage at heritage sites, seen suspicious activity at or near Dinorwig Quarry, or had information about those responsible to report it to the force.

The police said people should call 999 if a crime was taking place or there was an immediate risk to people or property. The emergency number is intended for incidents requiring an immediate police response.

People with information that does not require an immediate response should use the appropriate North Wales Police reporting channel. Witnesses should provide details such as the date and time of the incident, the exact location, descriptions of people or vehicles, and any available photographs or video.

Members of the public should avoid approaching suspects or putting themselves at risk. Information can be useful even if a witness does not know the identity of those involved, particularly when it includes timings, movements or vehicle details.

What is the wider significance for Gwynedd?

The police response highlights the challenges involved in protecting large industrial heritage sites. Quarries and former industrial areas can cover extensive landscapes, include isolated buildings and contain structures that are difficult to monitor continuously.

That combination can make sites vulnerable to vandalism, fire-setting and anti-social behaviour. Damage may affect buildings, machinery, walls, tracks, slate features and archaeological remains, while fires can create additional risks to nearby land, visitors and emergency responders.

Dinorwig Quarry’s inclusion within a UNESCO World Heritage Site landscape means damage can affect a place with importance beyond the immediate community. The police described the quarry as part of the industrial and cultural history of the area and said its features had national and international significance.

The reported incidents also create practical concerns for landowners and agencies responsible for access, safety and conservation. Security measures must protect historic features while allowing legitimate visitors and conservation work to continue.

Background: What is Dinorwig Quarry?

Dinorwig Quarry is a historic slate quarry in Gwynedd and forms part of the wider UNESCO World Heritage Site landscape associated with the slate industry in north-west Wales.

The location contains historic industrial remains, including structures and monuments connected with quarrying activity. The North Wales Police Rural Crime Team said some of those features are listed buildings or scheduled monuments, giving them additional legal protection.

The current police appeal follows what the force described as repeated incidents over recent months. Reported problems include criminal damage, anti-social behaviour and arson.

In response, North Wales Police said it would introduce additional security measures, including CCTV and a mixture of visible and covert patrols. The force is working with landowners and partner agencies as part of the effort to protect the quarry and support the preservation of its historic features.

Prediction: How could this affect visitors and local residents?

The immediate effect for visitors and local residents is likely to be a more visible police and security presence around Dinorwig Quarry. People visiting the area may see patrols, CCTV equipment or changes to site-management arrangements as landowners and agencies respond to the reported damage.

Access arrangements could receive closer attention, although North Wales Police has not announced that the quarry will be closed or that restrictions will definitely be introduced. Visitors should follow any signs, remain on authorised routes and avoid entering damaged or unsafe buildings.

For local residents, increased reporting of suspicious activity may lead to greater involvement in protecting the site. Community information could help officers establish when incidents occur and identify patterns that may not be apparent from individual reports.

The longer-term impact will depend on whether the new security measures deter further offences and whether those responsible are identified. If damage continues, landowners or agencies may consider additional restrictions, repairs or monitoring. If the measures prove effective, they could help preserve the quarry’s historic structures while supporting continued responsible access.

The central concern identified by police is the possibility that further damage could cause permanent loss. Protecting Dinorwig Quarry will therefore depend on coordinated enforcement, responsible visitor behaviour and timely reporting of incidents.