UNESCO World Heritage 2023

On September 17, 2023, Denmark’s five ring fortresses—Borgring, Aggersborg, Fyrkat, Nonnebakken, and Trelleborg—were inscribed on UNESCO’s World Cultural Heritage List. The inscription took place during the annual World Heritage Committee meeting, held in 2023 in Riyadh, the capital of Saudi Arabia.

The reason for their inclusion is that together they represent a unique period in world history, when Scandinavia transitioned from paganism to becoming an integral part of Europe’s Christian culture. The ring fortresses physically embody the turbulence of this era and stand as engineering marvels that mark Denmark as a newly unified kingdom.

All five fortresses were built between 970 and 980 AD during the reign of King Harald Bluetooth. Harald united the realm and made the Danes Christian, but not without battles. To secure his position, he constructed military bases that would demonstrate his power both domestically and abroad. The ring fortresses are thus part of the story of Harald Bluetooth’s ambitions to unify the kingdom and strengthen it against pressure from the Holy Roman Empire.

Background for Nomination to UNESCO World Cultural Heritage

The five Danish Viking fortresses—Borgring, Aggersborg, Fyrkat, Nonnebakken, and Trelleborg—were nominated for UNESCO World Cultural Heritage status in 2021 as a serial nomination, recognized for their history as well as their precise symmetrical and geometric construction.

The decision on their inscription was originally scheduled for 2022 at the annual World Heritage Committee meeting in Kazan, Russia. However, the decision was postponed due to the ongoing conflicts in Ukraine.