• da
  • en
  • de

Denmark’s largest round church

Østerlars round church is Bornholm’s, and Denmark’s, largest round church. It is also the most well-known of the four Bornholm round churches and receives about 120,000 annual visitors. The church is one of Bornholm’s most visited attractions.

Secret room

Erling Haagensen, a local author and researcher, is dedicated to exploring and understanding the mystery of Bornholm’s round churches. In his books, “Bornholms mysterium,” and “Tempelherrenes skat”, he argues that the Knights Templar might have been involved with the distinctive churches.

Ten and a half meters long, three meters high, and two meters wide. This is the size of a room hidden under the floor of the church at Østerlars. It was discovered with help of highly sophisticated measuring equipment. Unfortunately, approval has not been given to excavate this space in order to reveal the secrets it may contain. Many believe the Knights Templar have hidden the ark of the covenant here.

Why is it round?

Erling Haagensen also questions the common sense of the church’s function as a fortress. Haagensen punches holes in the theory with help of an article about the church from 1895, written by Colonel Otto Blom. It states that Østerlars round church, as a defensive location, is illogically placed and is impossible to defend, if the enemy comes close to the walls. In the case of a siege, one would further lack substantial practicalities like a well, toilet and kitchen facilities. 


Haagensen further believes that the round churches’ special construction, with a vacant center chamber, corresponds with Tycho Brahes Stjerneborg and Rundetaarn: two architectural buildings that precisely echo the measurements of the round church at Østerlars. The construction of the shooting portholes disagree with the fortress theory, but are well-suited for observing the skies at two very meaningful astronomical moments: mid-winder and mid-summer. Could it be that the church at Østerlars was actually built as an astrological observatory?

Take a closer look and explore yourself when you visit Denmark’s largest round church.

Others also read



Inge Lise Westman


Nordic Fermentation

Sandvig Minigolf