Trefoldighetskirken (Trinity Church), Oslo

Completed in 1858 and consecrated by Bishop Jens Lauritz Arup, the Trinity Church was designed by Hamburg-based architect Alexis de Chateauneuf, with later contributions by Wilhelm von Hanno, who refined the interior and completed the project following Chateauneuf’s death. Known for its neo-Gothic style, the building features an octagonal nave topped with a Greek cross and a prominent central dome, along with two slender octagonal bell towers framing the rectangular entrance.

The structure is built primarily from raw red brick, making it one of the few octagonal churches in Norway constructed from this material. The contrast between the red brick exterior and the grayscale tones of the vaults, arches, and small columns creates a distinctive visual character. Inside, the church could accommodate approximately 1,000 people, making it the largest church in Oslo and a prominent example of 19th-century ecclesiastical architecture in the country.

Trinity Church is also known for its interior artwork and craftsmanship. The altarpiece, depicting the Baptism of Jesus, was painted by Adolph Tidemand in 1866. The chandeliers, added in 1923, were designed by Emanuel Vigeland, and the stained glass windows were created by artist Frøydis Haavardsholm.

Currently, the church is closed and no longer functions as a place of worship. Once a notable religious site in the city, the building has been taken over by an international real estate group, and its future use remains unspecified. According to recent reviews, the site is not accessible to the public, and visitors can no longer enter or tour the interior.