On the evening of 5 November 2026, the Trinitatis complex in central Copenhagen, home to the Round Tower and Trinitatis Church, opens areas that are normally closed to the public. The evening is one of the events of LIGHT YEAR 2026, a jubilee year marking 350 years since Ole Rømer's discovery of the speed of light.
What you can see
- Secret rooms in the tower, including the Bell Loft, and the old apartment once used within the tower.
- The Library Hall, which hosts an exhibition on Ole Rømer and a reconstruction of his Jovilabium, a device that demonstrates the orbital movements of Jupiter's innermost moons.
- The newly restored Observatory, where staff offer guidance and, weather permitting, a chance to look through the telescope. Saturn can often be seen in November.
- The two crypts of Trinitatis Church, where Field Marshal Hans Schack and other 17th-century figures are buried.
Music and exhibitions
Organ demonstrations and performances alternate between the Italian Baroque organ and the main organ, combining stories with live music. Two exhibitions run during the evening: Ole Rømer and the Great Discovery and Light Echoes.
The visit suits anyone interested in astronomy, the history of science, or old Copenhagen buildings, and it gives a closer look at a site that is otherwise only partly open. Because part of the programme depends on the weather, the Observatory visit may vary on the night. More details and the full programme are on the Round Tower's website.