There is also Menelik's old Imperial palace which remains the official seat of government, and the National Palace formerly known as the Jubilee Palace (built to mark Emperor Haile Selassie's Silver Jubilee in 1955) which is the residence of the President of Ethiopia. Jubilee Palace was also modeled after Buckingham Palace in the United Kingdom. Africa Hall is located across Menelik II avenue from this Palace and is where the United Nations Economic Commission for Africa is headquartered as well as most UN offices in Ethiopia. It is also the site of the founding of the Organisation of African Unity (OAU), which eventually became the African Union (AU). The African Union is now housed in a new headquarters built on the site of the demolished Akaki Prison, on land donated by Ethiopia for this purpose in the south western part of the city. The Hager Fikir Theatre, the oldest theatre in Ethiopia, is located at the Piazza district. Near Holy Trinity Cathedral is the art deco Parliament building, built during the reign of Emperor Haile Selassie, with its clock tower. It continues to serve as the seat of Parliament today. Across from the Parliament is the Shengo Hall, built by the Derg regime of Mengistu Haile Mariam as its new parliament hall. The Shengo Hall was the world's largest pre-fabricated building, which was constructed in Finland before being assembled in Addis Ababa. It is used for large meetings and conventions. Itegue Taitu Hotel, built in 1898 (Ethiopian Calendar) in the middle of the city (Piazza), was the first hotel in Ethiopia.