The Rosenborg Castle expansion in Copenhagen is set to transform the visitor experience at one of Denmark’s most recognisable landmarks, with a new underground exhibition complex and a redesigned moat planned under the project Rigets Skatkammer (The Realm’s Treasury). The Royal Danish Collection (Den Kongelige Samling) says the upgrade will create more space for exhibitions and visitor facilities, while reintroducing elements of the castle’s historic setting in the King’s Garden (Kongens Have).
Rosenborg Castle expansion and the new underground treasury
At the core of Rigets Skatkammer is a new underground treasury designed to house a larger share of Denmark’s royal collections, including the crown jewels, regalia, and a major collection of historic costumes and ceremonial textiles. The Royal Danish Collection says the current layout leaves limited room for exhibitions inside the small Renaissance castle, and the new spaces are intended to make more objects available to the public, including items currently kept in museum storage.
The plan also includes new exhibition frameworks and modern visitor facilities to manage what the museum estimates at more than 500,000 guests a year. By shifting key displays underground, the project aims to expand capacity without altering the protected historic interiors of the castle.
Crown jewels, regalia and textiles: what the project wants to show
Rosenborg has long been associated with the material symbols of the Danish monarchy, but museum officials argue that today’s display conditions do not match the breadth of what the institution holds. Museum director Thomas C. Thulstrup said the new treasury should make it possible to show far more treasures than today, including objects that have been inaccessible to visitors so far.
The project is also framed as a way to strengthen Denmark’s position as a European cultural destination. The new underground spaces are expected to be curated as an atmospheric environment, focusing on the monarchy’s material history while creating a clearer narrative link between collections that are currently spread across limited rooms.
A moat returns: redesigning the approach to the castle
The second major element is a partial recreation and reinterpretation of Rosenborg’s historic moat (voldgrav). According to The Royal Danish Collection, the castle functioned as an island outside the city until the 18th century, an architectural idea the project wants to revive. A new bridge is planned as the main approach, with the aim of staging the transition from the city’s public park to the castle’s royal setting.
Supporters say the moat element is not only a landscape project, but a storytelling device: by bringing water back in some form, the museum argues the castle will regain a stronger visual identity and offer visitors a more coherent historical experience.
Funding: 661 million DKK for a major Danish culture project
The project has a total budget of 661 million Danish kroner (about €89 million), placing it among the largest cultural heritage investments in Denmark in recent years.
Funding is expected to come primarily from:
- A.P. Møller Foundation (A.P. Møller Fonden): 450 million DKK (about €60 million)
- The Danish state: 131 million DKK (about €18 million)
- Augustinus Foundation (Augustinus Fonden): 80 million DKK (about €11 million)
- The Royal Danish Collection’s own visitor facilities: 30 million DKK (about €4 million)
In the project’s public statements, both private foundations and the government have highlighted the balance between upgrading the visitor experience and respecting the protected setting of the King’s Garden.
