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H18: Halloween at Heureka
The highly popular H18: Halloween at Heurekassa science event will be held on Friday 31.10.2025 from 7 pm to midnight. The event is K18. Heureka is a drinking area during the event.
Advance tickets online: €18
Tickets on site, if any left: €20
Note: Museum cards, Heureka Club annual cards, Kaiku cards, press cards or Heureka free tickets are not accepted as payment for the event.
Psst! Photos will be taken at the event.
Sewer science for Halloween
In honor of the brand new water exhibition opening on 30.10.2025, the H18: Halloween science event will be celebrated with a sewer theme.
Come experience, sense and learn about the secret world of the sewers: who lives there and what can be found there? On top of that we also offer Halloween-related workshops and programs. This is an evening you don't want to miss. So grab a friend and dress up in your best Halloween costumes!
The program
The program is still being updated. Changes are also possible.
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Your evening as a cadaver dog
Our crime scene team is missing a cadaver dog: it's up to your team to be just that! Can you solve the crime mystery using only your sense of smell before it's too late? The fastest cadaver dog teams of the night will be rewarded!
Note! During the experience you will encounter strong smells and you may also encounter an actor.
The experience is organised in collaboration with Toneco.
7 pm–11.30 pm at the Giants of the Ice Age exhibition. The exhibition is closed throughout the evening. -
Dark alley
Can you complete the tasks in a dark alley?
Dark alley is based on the Pimé Café concept of the Finnish Association for the Visually Impaired . At the event, this dark alley is a reflection of the lives of the visually impaired.
Note! This is a multi-sensory experience - not a scary alley.During the event, you can also explore the Different Eyes exhibition , which is a Braille 200th anniversary exhibition organized in collaboration with the Finnish Association of the Visually Impaired.
7.00 pm–11.30 pm.
Drag Show
The evening will culminate in a terrifyingly awesome Drag Show. The evening's performers and schedule will be announced soon.
On the stage at the Event Square.
Drunken sewer balls
We will offer culinary science - molecular gastronomy - for adults. In the workshop you'll make your own green "caviar" with an adult twist! And what can you use this delicacy for? Snack on it, surprise your friends with your new skill, or add it to your drinks during the evening.
There are a limited number of places for the workshop. The workshop can accommodate 20 people per group and you can reserve your place by purchasing a €5 workshop ticket in advance through the link below.
Note! Once you have purchased the H18: Halloween event ticket , you will be able to log in to the workshop ticket purchase page . Purchasing a workshop ticket is only possible with the same email address you used to purchase the event ticket.
7.30 PM, 8.00 PM, 8.30 PM, 9.00 PM, 9.30 PM, 10.00 PM, 10.30 PM, 11.00 PM
Upstairs. Groups will be picked up by the spiral staircase next to the Giants of the Ice Age exhibition. The workshop's duration is 15–20 min.
20,000 Leagues Under the Sea
Come experience the magical VR experience called 20,000 Leagues Under the Sea . You will board Captain Nemo's legendary Nautilus on an interactive journey to the depths of the sea. You will experience Jules Verne's classic tale like never before - as the hero of your own underwater exploration! During the event you get to experience an amazing 3-minute version of the story.
The workshop is made possible by NOVA VRX. You can read more about the experience by clicking here.
7.00 PM–11.30 PM.
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Ikilehto: lecture and workshop
At the Ikilehto workshop "Design your own grave", you can design a grave site for yourself and talk to Ikilehto's caretakers about your funeral wishes. At the same time, you can take a photo of yourself in the Hukkapuu-coffin.
In addition, the caretakers of Ikilehto will give a lecture on the topic of having your own burial place in nature.
Workshop: 7pm – 11.30 pm.
The time and location of the lecture will be confirmed later. -
Wild rats
In the darkness of the city's shadows lurks a permanent resident whose existence everyone knows about, but few actually see. Santtu Pentikäinen, a researcher at the Helsinki City Rat Project, sheds light on what we know about the adaptation of the rat that roams sewers and garbage cans to the urban environment. The encounter between a human and a rat is often surprising and can evoke a variety of emotions - who gets the most scared?
The time and place will be confirmed later. -
Make yourself a backup brain
Did you forget your brain? No worries, in this workshop you can make yourself a new one! Plastic backup brains are made using a vacuum forming machine, after which you can decorate it to fit your on style and, if you want, wear it for the rest of the evening!
7.00 pm – 11.30 pm. -
Do you want to be a sewer master?
At the Science on a Sphere-site you can participate in a quiz full of questions about the wonderful world of sewers. Are you the sewer master?
The quiz will be held non-stop throughout the night. Each round will last for an indefinite period of time.
Fascinating lectures
The lectures will be presented in the auditorium. Grab some pop corn from the entrance of the auditorium to enjoy during the lecture, sit down in the comfortable chairs in the auditorium and enjoy the science of sewerage! The duration of one lecture is 20 minutes.
Note! The lectures are in Finnish.
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The shadow cosmos of the city: gods, spirits and sewers
On Halloween, we travel with an anthropologist to the sewers, whose dark dampness is teeming with ancient spirits, images of horror, rebellious gods and urban legends. Underground waterways have always been gateways to another reality. The sewer network is the shadow cosmos of the city, its wet flow associated with disgust, temptation and a touch of holiness.
The lecturer is Ninnu Koskenalho, anthropologist.
7.45 PM and 8.25 PM in the auditorium. -
Wastewater treatment in the Helsinki Metropolitan Area – everything you want (and don't want) to know
Wastewater treatment, like most critical infrastructure, is located and operates hidden from view, mostly underground. The lecture will explain how wastewater travels from residents to the treatment plant, how the treatment takes place, and where the treated wastewater ends up. We will also graphically demonstrate what happens when sewage is used as a garbage dump at pumping stations and treatment plants.
The lecturer is Kristian Sahlstedt, Head of Department, Wastewater Treatment, HSY.
9.05 PM and 9.45 PM in the auditorium.
Things to make the evening even better
Photography wall
Dressing according to the theme is not mandatory - but recommended! Please also go and take pictures of your awesome Halloween costume at the photo booth. This way we all get to enjoy the evening's costume splendor on Heureka's screens, where pictures are shown.
The Science Restaurant is open throughout the event
Drinks and snacks are available in the Science Restaurant and at the drink stations throughout the evening. Please note that only card payment is accepted.
