Culture Night with stargazing, winning photos and lighttrail

Finally, the newly restored Observatory is ready to welcome visitors, and the tower’s skilled astronomy guides are ready to take you on a journey into space. It is just one of the highlights of this year’s Culture Night programme at the Round Tower, where you can also see a unique collection of photographs on display in the Spiral Ramp.

This year, the Round Tower is celebrating the 350th anniversary of Ole Rømer’s discovery of the speed of light. That is why Culture Night 2026 will be an evening dedicated to light. We will illuminate the tower from bottom to top through the Spiral Ramp and turn our thoughts towards the universe.

The light will lead visitors up to the Observatory, which has reopened to the public following an extensive restoration. Here, visitors will have the opportunity to look through the historic, newly restored telescope and gaze out into the evening sky. If the weather permits it, there is a good chance that Saturn, among other celestial objects, will be visible.

At the Observatory, our astronomy guides will be on hand to help visitors navigate the night sky and explain what they are seeing through the telescope.

Winning Images and Astronomy Outreach

The illuminated Spiral Walk will also feature the winning images from the major photography competition that visitors to the Round Tower have been able to enter throughout the year. The competition has focused on the unique architecture of the complex and the special role that light plays within it.

As they make their way up through the Spiral Ramp, visitors will encounter the Round Tower’s astronomy guides, who will use engaging presentations and visual tools to share fascinating insights into the sun, moon, and stars.

Halfway up, in the Library Hall, visitors can experience two exhibitions exploring the theme of light. On the way into the hall, they will first encounter this year’s introductory exhibition, Ole Rømer and the Great Discovery, which tells the full story of the scientist and former director of the Round Tower, Ole Rømer, and his revolutionary discovery of the speed of light.

Inside the Library Hall, the fourth and final exhibition in this year’s series exploring light unfolds. Light Echoes brings together artists, curators, and astrophysicists in an exhibition exploring how the connection between light and time shapes our understanding of cosmic phenomena. Through four installations and an immersive soundscape, scientific knowledge unfolds as an experiential and immersive field rather than a fixed image.

There is limited capacity both in the Round Tower and at the Observatory, so please be aware that queues may occur.

Please note: The Round Tower cannot guarantee that celestial objects will be visible through the telescope if weather conditions do not permit it. If the weather is unsuitable, the Observatory will still be open, and the Round Tower’s astronomers will share more about the Observatory and its impressive telescope, which can magnify objects between 80 and 450 times.

Please note: Admission is only possible with a Culture Pass on this evening. The Culture Pass will be available in early October.

Workshop: Paint Black Holes with Light

Meet researchers from the Center for Gravity at the Niels Bohr Institute and explore the fascinating world of gravity as we create striking images of black holes painted with light.

A black hole is a region in space where gravity is so strong that nothing can escape – not even light. Yet scientists can still study them by observing their surroundings: watching stars orbit them, detecting ripples in spacetime when black holes collide, and even capturing images of light bending around them. In this workshop, you’ll discover how researchers observe black holes and learn more about these mysterious cosmic phenomena.

With guidance from experts from the Center for Gravity at the Niels Bohr Institute, you’ll design your own black hole on paper before bringing it to life by painting it with light. By keeping a camera’s “eye” open for a long time, it can collect more light – the same technique used to capture spectacular images of distant nebulae and galaxies. Using this method, along with a variety of light sources including flashlights and fairy lights, you’ll create your very own black hole. Afterwards, your finished image will be sent to your phone, or to the phone of the adult accompanying you, so you can keep it as a souvenir.

The workshop is part of Black Hole Week, organised by the Center for Gravity, a Center of Excellence at the Niels Bohr Institute dedicated to research into gravity, black holes and the most extreme phenomena in the universe.

The workshop takes place at Rundetaarn, is included in the standard admission ticket, and requires no advance booking. The workshop facilitators speak both Danish and English.

guests will also have the opportunity to explore the exhibitions Refractions of Ice and Ole Rømer and the Great Discovery, Rundetaarn’s introductory exhibition. Visitors are also welcome to walk up the beautiful Spiral Ramp to the top of the Tower and enjoy the panoramic views over Copenhagen.

The workshop is part of Rundetaarn’s LIGHT YEAR 2026 programme, marking the 350th anniversary of Ole Rømer’s discovery of the speed of light.

Monster workshop with Shane Brox

Fangs, scales, or a serpent’s tongue? Bring mysterious and monstrous creatures to life when multi-artist Shane Brox invites you to an imaginative and creative monster workshop at the Round Tower.

Using quirky materials, colors, and shapes, children and adults can create their very own monsters with exactly the features they find most frightening. The workshop is a playful free space where imagination takes the lead, and where even the strangest ideas can become fantastic and terrifying creatures.

Shane Brox is a multi-artist who has created television programs and written children’s books. He makes sculptures in many different forms and sizes, working especially with recycled materials. Throughout the workshop, Shane will offer help, advice, and creative ideas.

The workshop requires no registration and is open to all little monsters and their grown-ups, with drop-in access throughout the event. Participation costs only the regular admission fee to the tower, and all materials are provided. Come and enjoy some spooky fun!

Also visit the exhibition

Need a breather? Take a walk through the current exhibition Refractions of Ice and explore patterns of ice crystals under polarized light. Perhaps the colorful, melting ice crystals will inspire your monster creation?

The workshop is part of the Golden Days Festival, where this years theme is “Monster.”

In Ole Rømer’s footsteps

Go hunting for celestial objects and astronomical instruments in the winding Ramp, and help Ole Rømer make his great discovery.

How did Ole Rømer discover that light has a speed? And what did he need in order to figure it out?

Children and the young at heart can explore the Ramp’s windows and collect stickers to learn more about Ole Rømer’s discovery of the speed of light, the 350th anniversary of which is being marked this year by the Round Tower.

In the Library Hall, halfway up, you can also learn more through the exhibition Ole Rømer and the Great Discovery and explore the current special exhibition too!

The children’s activity runs during school holidays for the rest of the year as part of Light Year 2026.

Create Stunning Blue Images with Cyanotype

Experience the magic of light in this family workshop.

How can light create images in captivating shades of blue? You and your family can find out when the Round Tower, in connection with the photo exhibition Ad Lucem, invites children and adults to a creative workshop.

Together with artist Cecilia Ömalm and astronomy professor Göran Östlin—the creators of the exhibition—you’ll have the chance to make your own light prints using cyanotype, a historical photographic technique invented by astronomer John Herschel. The technique traditionally uses iron salts mixed into UV-sensitive solutions which, together with sunlight, form images in characteristic deep-blue tones.

In this workshop, we work with UV light and small glass negatives featuring space-themed motifs, which we will transform into beautiful cyanotypes.

Join us for a creative family workshop that brings together art, science, and curiosity—where you’ll learn the technique and take home your own blue masterpieces! With the same ticket, you can also explore the exhibition and the rest of the Round Tower.

Lantern Walk for Children

Join us for a special evening for families with children in the Round Tower, where we brighten the darkness and create artistic lanterns.

Have you ever experienced the Spiral Ramp in the dark? Find your way to the open workshop in the Library Hall, where you can craft your own imaginative lantern to help you find your way further up through the tower.

Afterwards, you can go exploring with your glowing lantern — and with your parents — in hand, all the way to the top of the old tower.

Please note: This event is for families with children only and is part of the programme for LIGHTYEAR 2026 at the Round Tower — a full year in which we celebrate light and the 350th anniversary of Ole Rømer’s groundbreaking discovery of the speed of light.

Workshop: Paint with Light

Join us as we play with light and long exposure times to create beautiful images together with astrophysicist and head of the Round Tower’s observatory, Christina Toldbo.

What is light? And how did the Danish astronomer Ole Rømer discover 350 years ago that light has a speed? Get the answers when the Round Tower’s observatory director, Christina Toldbo, tells more about astronomer Ole Rømer and his major discovery, which remains important to us today.

When we capture light from the Universe with our bare eyes, there’s a limit to how long we can keep them open. Luckily, we have cameras that can collect light for much longer! This is why astrophotographers can take stunning photos of faintly glowing nebulae and galaxies.

In this workshop, we’ll also use cameras to collect light and create light art with long exposure times and different light sources — including flashlights and Christmas lights! You’ll even get to print your own light-art photo and take it home with you.

Workshops will be held on both February 9 and 10 from 11:00 to 13:00.
Participation is free once admission to the Round Tower has been paid.

Family Workshop: A Shadow of the Universe

During autumn break, children and their parents can join a creative shadow-cutting workshop and contribute to a larger collage of cosmic stories.

Anything is possible when Tomas Lagermand Lundme, author and visual artist, create shadow cuttings and shadow motifs in different forms of cut-outs together with the workshop participants.

The various cut-outs of shadows and shadow stories are continuously assembled throughout the event into a larger collage of cosmic tales about the shadows we each carry, whether they are short or long, or both.

It is sure to be a moving, humorous, and whimsical afternoon.

The workshop is open to everyone, and you are free to come and go as you like, participating for as long as you wish. No prior experience is required – only the desire to play along.

Astro Night for Families

Join us for an evening of astronomy for kids as we open the Observatory specially for families this autumn break.

It’s cold at the top, so grab your warm sweater as we invite families to visit the Observatory and point the telescope lens towards Saturn or the Moon if weather permits.

The Observatory can only hold a number of guests at a time, so explore the Spiral Ramp too where our observators will unfold tales of astronomy and the heavenly bodies at eye-level with kids.

Stop at the Library Hall to buy a cup of hot cocoa on your way up or down the tower.

Please Note: Star and planet gazing is not possible if the sky is overcast.
The Round Tower cannot guarantee visible heavenly bodies if the weather does not permit. If it is cloudy or overcast, our astronomers will still keep the Observatory open for visits and will in stead tell stories about the telescope, the night sky and the old Observatory.

Tickets include entry fee but must be pre-booked.

Culture Night

Visit us after hours on this special evening, as the Round Tower shines a light on hidden stories in art, music and astronomy.

The evening’s program is inspired by the current exhibition “The Shadow Archive” which conveys stories of the forgotten, the unforeseen, and the shadowless. Exhibitors Al Masson and Tomas Lagermand Lundme will perform a piece based on their works in the exhibition, each dealing in their own way with archiving and remembering – for better or for worse. Masson focuses on the media, on what has been told and thereby remembered, while Lundme’s performance is an audience-engaging long poem in Danish about the Round Tower in the heart of the city, where people have met, and still can meet, the stars at eye level.

In the Spiral Ramp, visitors can learn about women in astronomy whose names have been forgotten or overlooked, but whose discoveries and inventions have had a great impact on astronomy today. The tower’s skilled observers will also walk the ramp, meet young and old guests at eye level and unfold stories of the mysteries that the Universe holds.

For the very first time, astronomy will also move outside the tower. Waiting guests will be able to experience street astronomy and ask questions to the tower’s observers. Be aware, that if it is cloudy or raining, there will not be any street astronomy.

At the top of the tower, visitors can, as always, look for constellations and planets through the old telescope if weather permits.

At 11 PM, a concert will take place in the Library Hall, as clarinetist Jonas Frølund and the Nightingale String Quartet perform a composition by Bent Sørensen. The Nightingale String Quartet consists of Gunvor Sihm and Josefine Dalsgaard, violins, Marie Louise Broholt Jensen, viola, and Louisa Schwab, cello. The group has won the award P2 Artist of the Year in 2025.

Program

18:00–23:00
The exhibition “The Shadow Archive” is open to guests in The Library Hall

18:00–00:00
The Observatory is manned and open to guests – please note that in case of rain or clouds, the sky is overcast and planets or stars won’t be visible through the telescope. In case of bad weather, the Observatory will remain open to guests and our observers will still always be able to provide guidance and stories of the heavenly bodies, the telescope or the old observatory.

18:00–00:00
Stories of women in astronomy in the Spiral Ramp

19:00 & 20:00
Performance with Al Masson and Tomas Lagermand Lundme (in Danish), duration: approx. 25 minutes

23:00–23:40
Concert with Jonas Frølund and the Nightingale String Quartet in the Library Hall