The Pergamon Museum is a listed building on the Museum Island in the historic centre of Berlin, Germany. It was built from 1910 to 1930 by order of Emperor Wilhelm II and according to plans by Alfred Messel and Ludwig Hoffmann in Stripped Classicism style. As part of the Museum Island complex, the Pergamon Museum was added to the UNESCO World Heritage List in 1999 because of its architecture and testimony to the evolution of museums as architectural and social phenomena.