How can a historical hunt for a missing SS Officer increase museum visits by 30%?

Kamp Amersfoort is rarely the first Dutch concentration camp to come to mind, although 47,000 people were imprisoned there during World War II. How could we help attract more visitors to the National Museum Kamp Amersfoort? The solution: to tell the unique story about the camp’s founder and his mysterious disappearance in 1945: Walter Heinrich. Telling the story: iO podcast maker Jordy Hubers and Floris van Dijk, Head of Research at the National Museum Kamp Amersfoort. For eight weeks their informative podcast held the number one spot in the Apple Podcast history charts. And the camp itself? National Museum Kamp Amersfoort saw a 30% increase in visitors. Telling the story: podcast maker Jordy Hubers and Floris van Dijk, Head of Research at the National Museum Kamp Amersfoort. For eight weeks their informative podcast managed to take hold of the number one spot in Apple Podcast’s history charts. And the camp itself? Kamp Amersfoort saw a 30% increase in visitors.


National Monument Kamp Amersfoort


Attract (potential) visitors to the museum


An eight-part podcast via fully owned channels

About National Monument Kamp Amersfoort

When you say, ‘Second World War’ and ‘concentration camps in the Netherlands’, Kamp Westerbork or Kamp Vught immediately spring to mind. Kamp Amersfoort is rarely mentioned. Yet 652 people died and 47,000 people were imprisoned there by the horrific regime.  

So, the challenge for National Monument Kamp Amersfoort; how do you encourage people to visit your museum? How can we combine physical and digital experiences so that they complement and enhance each other? How do you get a real story to a wide audience, and thus spark the interest of potential visitors? 

Listen to the podcast on Spotify:

A podcast is the best medium for sharing real stories

There is only one medium to tell a story like this in a compelling way: a podcast. Social media channels have a character maximum, YouTube is snackable media, where users tend to skip between clips and blogs are expected to be short and to the point.

A podcast is a great medium to tell a complex story about real-life events. But in a remarkable place like Kamp Amersfoort, there are at least 47,000 stories to tell. Several are already highlighted in the museum. The question: how do you get all the stories into a podcast series? The answer: you don’t.

We chose to highlight one story. A story that hardly featured in the museum, that there wasn’t much to share about at the time. Because this podcast turned out to be more than a powerful audio story that was full of suspense and twists. It became a series that chronicled the process of historical research into one of the most important people in the camp: its founder Walter Heinrich.

NOS news broadcast about this podcast

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iO and Nationaal Monument Kamp Amersfoort created an eight-part podcast: The Missing SS Officer. A poignant audio story that has been listened to almost a million times.

“As makers, our starting point was the same as always: we wanted to tell a solid, exciting story. A podcast that combines entertainment and education. With healthy listener numbers, that are already well on the way to reaching the one million mark, we succeeded in introducing a wider audience to the National Monument Kamp Amersfoort.”

Jordy Hubers

Jordy Hubers, Podcast Creative iO

The search for Walter Heinrich

Walter Heinrich was a war criminal, a mass murderer, and the founder of one of the most gruesome concentration camps in the Netherlands during World War II. In February 1945 he disappeared without a trace. What happened to him?

In ‘De Verdwenen SS’er’ (translation: The Missing SS Officer), iO podcast maker Jordy Hubers and Floris van Dijk, Head of Research at National Monument Kamp Amersfoort, went looking for the answer. They investigated all possible leads. Was he killed during the fall of Berlin? Was he a prisoner of war? Did he successfully escape to the other side of the world?

After nine months of research, Jordy and Floris came to surprising discoveries that made national headlines, with a feature on the NOS nightly broadcast news as icing on the cake, bringing the story to 2.4 million viewers. Research carried out during the podcast revealed that Walter Heinrich’s wartime crimes were far worse that had previously been established, and that he was responsible for at least 625 deaths.

The collaboration in numbers




increase in visitors


weeks at #1 in the History category (Apple Podcasts)

Top 10

in the charts (Spotify)


score on average (Apple Podcasts & Spotify)

One of the best branded podcasts in the Netherlands

The podcast was promoted only on owned channels and with free publicity. Thanks to articles and features in the national and regional media, the podcast went viral. With over 850,000 downloads, it made its way to top-ranking positions on both Apple Podcasts and Spotify.

But that's not all. The initial aim was to attract more visitors to National Monument Kamp Amersfoort. And it worked. After the podcast went live in October 2022, the camp saw a visitor increase of 30% compared to the previous month. Where the 'quiet' season traditionally starts from September, in October 2022 there were more visitors than in August.

“In the end, we put a face and a story to a war criminal who was previously unknown in the Netherlands — filling in some serious gaps in our shared history and knowledge. Along with boosting the museum’s profile and increasing engagement and visitor numbers, I think, even though you have to be careful making statements like this, that ‘The Missing SS Officer’ is the best branded podcast at the moment.”

Jordy Hubers

Jordy Hubers, Podcast Creative iO

Branded podcasts

A strong branded podcast starts with identifying the best stories, coming up with the right format, and choosing the most effective release frequency. iO will guide you through the process.

Podcast opname de verdwenen SS'er
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