Experience the secrets of the Trinitatis Complex

On this November evening, the Trinitatis complex celebrates the light by opening its doors to hidden spaces that are normally not part of the visitor experience. Come behind the scenes at the Round Tower and Trinitatis Church, where you can explore the old apartment and the church crypts, learn more about Ole Rømer, hear music from the church organs, and catch a glimpse of the night sky from the Observatory.

As part of LIGHT YEAR 2026, a jubilee year marking the 350th anniversary of Ole Rømer’s discovery of the speed of light, the Trinitatis complex are opening up areas of the church and tower that are normally closed to visitors on this winter evening, inviting all visitors to enjoy a range of exciting experiences.

Secret rooms, stargazing and the Jovilabium

At the Round Tower, special access will be granted to secret rooms that are otherwise closed to the public. These include the Bell Loft, one of two loft spaces belonging to Trinitatis Church. Sounds strange? Come and see for yourself. The secret tour will also take you to the old apartment, offering a glimpse into life in the tower during Ole Rømer’s time as well as today.

In the Library Hall at the Round Tower, visitors can enjoy an exhibition about the astronomer Ole Rømer, who was, among other things, director of the Observatory and chief librarian of the library at the Trinitatis complex. Visitors will also have the opportunity to see a reconstruction of Ole Rømer’s remarkable Jovilabium – a fascinating mechanical and astronomical instrument that demonstrates the orbital movements of Jupiter’s innermost moons.

At the top of the Round Tower, in the newly restored Observatory, visitors can learn more about the universe – both by exploring how the nearly 100-year-old telescope is used today and how the tower was used for astronomical observations in the 17th century.

Weather permitting, it will also be possible to look through the telescope yourself and experience fascinating celestial objects – in November Saturn and its spectacular rings can often be seen in the evening sky.

Crypts and organ music

At Trinitatis Church, visitors will have access to the two crypts, where Field Marshal Hans Schack and other prominent figures from the 17th century are buried in elaborately decorated coffins. You can learn about Trinitatis Church as it looked when it was inaugurated in 1656, as well as about Hans Schack, who organised the defence of Copenhagen during the Swedish siege.

Visitors will also have the opportunity to get close to the church’s organs and learn more about both the Italian Baroque organ and the main organ through stories and live music.

All this can be experienced

At Trinitatis Church

• Access to the crypts
• Access to Hans Schack’s monument and the sacristy
• Alternating organ demonstrations and performances

At the Round Tower

• Access to the Library Hall and the two exhibitions: Ole Rømer and the Great Discovery and Light Echoes
• Demonstrations of Ole Rømer’s planetary machines at several special locations in the tower
• Access to the Observatory, with the opportunity to look through the telescope (weather permitting), as well as guidance from the observatory staff
• Astronomy presentations and a demonstration of Ole Rømer’s Jovilabium

Practical information

It is possible to register in advance via the link on the right, but you can also simply turn up at the Round Tower ticket office. The evening costs the regular admission price (DKK 60 for adults / DKK 40 for students / free admission for children). The church can be accessed through a glass door connecting the church and the tower, an area that is normally closed to visitors.