DETECT KNOWLEDGE CENTRE | SAFE & RESPONSIBLE DETECTING

Found a rare old coin, a historical buckle, a suspicious metal object or something that might be an explosive?

Not every discovery should be handled in the same way. With an archaeological find, preserving information is important. With a potentially dangerous object, personal safety must always come first.

This guide explains what to do in the Netherlands if you discover historical objects, coin hoards, old weapons, ammunition, suspected explosives or possible human remains.

Based on the Dutch original, last reviewed on 17 October 2026.

Found a suspected explosive? Stop and call 112

If you suspect that an object is a grenade, mine, bomb or other explosive device:

• Stop detecting and digging immediately.
• Do not touch or move the object.
• Do not attempt to clean, open or identify it by handling it.
• Do not return to take photographs at close range.
• Keep your distance and keep other people away.
• Call 112 in the Netherlands and follow the emergency services' instructions.

Official guidance: Dutch Ministry of Defence – Found a suspected explosive?

1. What have you found? A practical guide

While metal detecting, you may discover many types of objects. Some can be recorded and carefully stored, while others require you to stop immediately.

Important: Never attempt to determine for yourself whether a suspicious object is safe.

2. Unusual historical finds discovered with a metal detector

For many detectorists, finding a special historical object is the highlight of the hobby. An old coin, brooch or buckle may have been buried for centuries.

Its archaeological value is not determined by age or rarity alone. The exact location and circumstances of the discovery may provide valuable historical information.

What kinds of historical objects might you discover?

What should you do with a historical find?

1. Look for signs of other related objects or unusual features nearby.
2. Record the exact location and date.
3. Photograph the object in its original condition.
4. Store objects safely when there are no signs of danger.
5. Report archaeological discoveries to PAN or the RCE.

If you suspect an intact archaeological feature or a group of associated objects, stop digging and seek advice from an archaeological specialist.

3. What if you find a coin hoard or treasure?

A coin hoard is a collection of coins that may have been deliberately deposited or hidden together. Groups of other historical objects can also form an important archaeological discovery.

The arrangement of individual objects and their precise position in the ground can be as important as the objects themselves.

Why should you leave the objects together?

Their original arrangement may help archaeologists determine whether they were buried at the same time, belonged to a building or were connected to an important historical event.

Removing everything without proper documentation can destroy that information permanently.

Is every coin hoard legally considered treasure?

No. An archaeological coin hoard and treasure under Dutch property law are not necessarily the same. Legal ownership depends on the circumstances and applicable legislation.

Archaeological finds must be reported regardless of who eventually owns them.

4. Finding old ammunition or explosives

Unexploded ordnance from past conflicts, particularly the Second World War, can still be found in Dutch soil.

During metal detecting, you might encounter a grenade, landmine, mortar ammunition or another suspicious object.

Old or heavily corroded ammunition can still be dangerous. You cannot reliably judge safety from its appearance.

What should you do if you suspect an explosive?

1. Stop searching and digging immediately.
2. Keep your distance from the suspicious object.
3. Do not touch or move it.
4. Do not uncover, clean, open or transport it.
5. Keep other people and animals away.
6. Call 112 in the Netherlands and follow the emergency services' instructions.

Can you take old ammunition home?

No. Never take suspicious ammunition home. Apart from the potential danger, possession or transportation may also be illegal.

Do not bring it to a shop or police station. Let the police assess the situation at the discovery location.

Who deals with unexploded ordnance?

The police may involve the Dutch Explosive Ordnance Disposal Service, known as the EOD (Explosieven Opruimingsdienst Defensie). This specialist military service assesses and disposes of explosive hazards.

Read the Dutch Ministry of Defence's official guidance →

5. Old weapons and military objects

Metal detectorists occasionally discover military objects, including equipment, weapons components and ammunition.

Not all military objects are dangerous, but appearance alone cannot establish whether an object is safe or legal to possess.

Found an old firearm?

Do not pick it up, attempt to operate it or take it home. Contact the police for instructions. If you suspect an explosive hazard or immediate danger, call 112.

Found a military helmet, buckle or identification item?

Historical equipment may be archaeologically important. For objects that are clearly safe to handle, record the location and report archaeological discoveries as required.

If such objects are found alongside possible ammunition, weapons or human remains, stop immediately and contact the police.

6. What should you do if you find human remains?

Possible human bones or a burial site must be treated with particular care. You cannot reliably determine their age or origin without specialist examination.

How should you respond?

1. Stop detecting and digging immediately.
2. Leave the remains and surrounding objects in place.
3. Do not disturb the immediate area further.
4. Keep other people away from the discovery site.
5. Contact the Dutch police. Call 112 if there is an immediate danger.
6. Follow official instructions and leave further investigation to the appropriate authorities.

Even if you believe the remains are very old, do not continue excavating them yourself.

Why is the original position important?

The relationship between remains and nearby objects may be vital to both police investigations and archaeological research.

Preserving the site is therefore more important than recovering individual objects.

7. How should you store an unusual historical find?

If an object is safe to handle and there are no signs of danger or an undisturbed archaeological feature, you can store it carefully while awaiting registration or specialist advice.

Five tips for preserving historical finds

1. Record the location: Keep GPS coordinates, the discovery date and other relevant details.
2. Take photographs: Document the object before cleaning, preferably alongside a scale.
3. Store finds separately: Use appropriate individual packaging and labels.
4. Be careful with cleaning: Avoid harsh chemicals, abrasive tools and hard brushes without specialist advice.
5. Seek expert advice: Fragile metal objects and unusual historical artefacts may need professional conservation.

Should every old object be cleaned immediately?

No. Inappropriate cleaning can damage historical surfaces, decorations and traces of other materials. It is often best to photograph the object first and ask a specialist for advice.

8. Where do you report unusual archaeological discoveries?

Archaeological finds must be reported in the Netherlands. The Cultural Heritage Agency of the Netherlands (RCE) provides official information and a reporting form. Finds may also be reported through Portable Antiquities of the Netherlands (PAN).

Useful information includes the exact location, date, photographs and a description of the object.

Safety always comes before reporting

If you suspect an object may be explosive or otherwise immediately dangerous, do not treat it as an ordinary archaeological discovery. Keep your distance and contact emergency services first.

Frequently asked questions about unusual and dangerous metal detecting finds

What should I do if I find a grenade?

Do not touch or move it. Keep your distance, stop detecting and call 112 in the Netherlands.

Is ammunition from the Second World War still dangerous?

Yes. Old ammunition can remain dangerous after many decades. Never try to assess its safety yourself.

Can I take a found bullet or grenade home?

Never take suspicious ammunition home or attempt to transport it. It may be dangerous and subject to legal restrictions.

Do I have to report an old coin?

Archaeological coin finds must be reported. You can use PAN or the RCE reporting system.

What if I find several old coins together?

Stop further digging if you suspect a related archaeological group. Preserve the location and seek professional archaeological advice.

What should I do if I find human bones?

Stop digging, leave everything in place and contact the police. Call 112 if the situation is immediately dangerous.

Can I keep an old firearm I found?

Do not assume you can. Firearms and components may be subject to legal restrictions. Do not handle the item further and ask the police for instructions.

Can a heavily rusted metal object still be explosive?

Yes. Corrosion and age do not make explosive ordnance safe.

Must I surrender an unusual archaeological find?

Not automatically. Reporting and legal ownership are separate questions. Special discoveries may be subject to additional requirements.

Should I clean an unusual historical find immediately?

Not necessarily. Cleaning can damage fragile historical material. Document it first and seek conservation advice if needed.

Do the same rules apply in the UK or Ireland?

The general safety advice is broadly relevant, but this article's legal and archaeological reporting guidance concerns the Netherlands specifically.

Official sources and important information

• Dutch Ministry of Defence – Suspected explosives
• Cultural Heritage Agency – Reporting archaeological finds
• Cultural Heritage Agency – Metal detecting regulations
• Official archaeological find reporting form

This guide provides general information and is not a substitute for professional safety advice, emergency service instructions or legal advice. For dangerous discoveries, the police and emergency services' instructions always take priority. Laws and reporting procedures may change.

Safe and responsible detecting with Detect

Metal detecting is not just about discovering interesting objects. It also involves respecting history, nature and your personal safety.

At Detect Metaaldetectors, we help new and experienced detectorists with suitable equipment, practical knowledge and personal advice.

If you encounter a dangerous discovery, always contact the appropriate emergency services rather than a retailer.

Detect Metaaldetectors – specialist knowledge, honest advice and service.