Oslo University Hospital (Norwegian: Oslo universitetssykehus; OUS) is a university hospital in Oslo, Norway. With over 24,000 employees it is the largest hospital organization in Europe. It is affiliated with the Faculty of Medicine of the University of Oslo and is one of the largest medical research institutions in Europe. Its oldest predecessor, Rikshospitalet (The National Hospital), was established as Norway's national teaching hospital in 1826 mainly on the basis of the Military Hospital founded in 1807, while its academic tradition dates back to the establishment of the Faculty of Medicine in 1814. From the late 19th century the hospital was established as one of Europe's most modern hospitals and leading medical research institutions. Oslo University Hospital was formed by the merger of the then-three university hospitals in Oslo in 2009.The hospital includes 325 buildings that are primarily spread across four main campuses in Oslo: Rikshospitalet, Ullevål, Aker and Radiumhospitalet. It is one of two university hospitals affiliated with the University of Oslo, alongside Akershus University Hospital. Source: Wikipedia (en)