Leiden is one of the prettiest cities in the Netherlands. I don’t think anyone can deny that fact. But don’t be fooled by those charming little alleys full of bicycles and flowers. There is a lot more to discover than first meets the eye. With well over a thousand years of history, Leiden also conceals a darker side that most people will never encounter. Together with my friend Flora, a Leiden local, I uncovered several hidden stories about horrific tragedy and cunning murders. Who knows, some of these places might even be…haunted (cue the high-pitched shrieking in the background). Just wait until you hear the stories, and I’m sure you will think so too.
This is the Dark Side of Leiden
The Serial Killer of Leiden and her Deadly Poison
I don’t think many Dutch people are aware of this unimaginable story: Leiden is the home of a Guinness World Records serial killer. If you think it was a brutish man with an anger issue, you are most definitely mistaken. A (seemingly) lovely lady nicknamed Goeie Mie (Good Mie) was an important figure in 19th-century Leiden. Initially, everyone thought she took loving care of children and nursed the sick back to health. Her reputation, however, radically changed after the discovery of at least 27 murders.
Goeie Mie or Maria Swanenburg grew up in a poor family, as her father spent most of his money on alcohol. This could explain why she became so dangerously obsessed with money and power. You see, Goeie Mie was able to murder so many people without being caught, because her weapon of choice was invisible: she poisoned her victims with arsenic powder by mixing it in their food.
Goeie Mie was able to murder so many people without being caught, because her weapon of choice was invisible: she poisoned her victims with arsenic powder.
Before she murdered any of her victims, she always made sure to arrange a funeral insurance. This is how she earned incredible amounts of money, which she, strangely enough, never really spent on anything. When three family members all died at the same time, the people of Leiden finally grew suspicious. Goeie Mie was unmasked as the killer in 1885. She spent the rest of her life in prison after becoming the deadliest poison mixer of all time.

The Gravensteen Prison Executions
The medieval Gravensteen is one of the oldest buildings in Leiden. It currently houses university lecture rooms, but it was far from an ‘intellectual’ space in the Middle Ages. The Gravensteen started its life in the 13th century as the residence of well-to-do earls from Holland. The earls decided to turn part of their residence into a private prison and the old chains that were used to extort the inmates still remain in the basement.
By the 15th century, the earls handed the Gravensteen over to the city of Leiden. The building became the official city prison and death penalties were now publicly executed in front of the Gravensteen. You can still visit this execution site today, now a peaceful little square in the historic heart of Leiden. The final execution of a man called Janus van der Blom took place in 1853. Van der Blom was hanged for the “beastly murder” of a little girl.

The Van Der Werffpark Gunpowder Disaster
Today, the Van der Werffpark in Leiden is a wonderful place to relax in the sunshine, catch a breath of fresh air, and enjoy a drink at the quaint little tea house. Nobody would suspect this place to have been the site of a horrific tragedy. The truth is, however, that this park would have never even existed if it wasn’t for an atrocious explosion in January 1807.
This park would have never even existed if it wasn’t for an atrocious explosion in January 1807.
On a cold winter’s night, one of the ships on the Steenschuur canal suddenly caught fire and exploded. Unfortunately, this wasn’t any ordinary explosion, because the ship contained a heavy load of gun powder. An entire neighbourhood was blasted to pieces, 2000 inhabitants were injured, and about 160 were killed. All that remained was rubble and ashes, and the former neigbourhood was left untouched for years on end. The ruins eventually made way for a new city park in 1886.

The Truth Behind the Deadly Morspoort
The Morspoort (Mors Gate) was the western city gate of medieval Leiden. The gate is still one of the most picturesque hotspots in historic Leiden. Unsurprisingly, it is quite a popular location for wedding pictures, but there was little reason for celebration in medieval times. Yet again, the final story tells a tale of murdered prisoners.
The unofficial nickname of the Morspoort reveals its true history: many locals prefer to call it the Galgenpoort, or Gallows Gate. A long time ago, there was a marshy grassland called ‘De Morsch’, right outside the gate. This was the location of the city’s largest gallows field, where countless prisoners met their grisly ends.

More about the Netherlands:
Interested to know more about the cultural gems and natural landscapes you can discover in the Netherlands? I hope so! Perhaps some of the articles I’ve written so far can help you find inspiration for your next trip: