Trinity Church, known in Norwegian as Trefoldighetskirken, is a prominent Neo-Gothic landmark located in the Hammersborg neighborhood of central Oslo. Consecrated in 1858, it is one of the city’s largest churches with a seating capacity of approximately 1,000 people. The building is architecturally unique for its red brick construction and an octagonal floor plan superimposed with a Greek cross, topped by a large central dome and two slender bell towers. Originally designed by architect Alexis de Chateauneuf and completed with modifications by Wilhelm von Hanno, the interior features significant Norwegian artistry, including an altarpiece by Adolph Tidemand, stained glass by Frøydis Haavardsholm, and chandeliers designed by Emanuel Vigeland.