The Museum Island is an island of museums. It has been a part of the UNESCO world heritage since 1999. It is located on an island in the Spree River in central Berlin, which is located in the Mitte district. It gets its name from the many museums that can be found there. The site was founded by Frederick IV of Prussia in the late ninetieth century and started off as a residential area that was devoted to science and the arts. The collections were made public after the First World War, and now the foundation is managed by Prussian Cultural Heritage. These collections were divided during the separation of the two Germanys, but now they are together again.