Rådhus

This twin-towered city hall, completed in 1950 to commemorate Oslo's 900th anniversary, houses the city's political administration and is filled with mid-century artistic tributes to Norwegian cultural and working life. Something of an Oslo landmark, its austere, red-brick functionalist exterior is unmissable, if polarising. It's here that the Nobel Peace Prize is awarded on 10 December each year. All visitors must pass through airport-style security.