The Pergamonmuseum was designed by Alfred Messel; its construction was overseen by Ludwig Hoffmann and lasted twenty years, from 1910 to 1930. A smaller building initially stood on the same site for a just few years before being torn down. It housed the important excavation finds unearthed by the Berlin museums, such as the frieze panels from the Pergamon Altar, reclaimed from the earth in digs that lasted from 1878 to 1886. Inadequate foundations, however, soon resulted in the building becoming structurally unstable and it had to be demolished. The new, larger Pergamonmuseum was built as a three-wing complex. The museum now houses three of the Staatliche Museen zu Berlin’s collections: the Antikensammlung, Vorderasiatisches Museum, and the Museum für Islamische Kunst. The impressive reconstructions of massive archaeological structures – the Pergamon Altar, Market Gate of Miletus, the Ishtar Gate and Processional Way from Babylon, and the Mshatta Facade – have made the Pergamonmuseum famous throughout the world, with the result that it is the most visited museum at the Staatliche Museen and in Germany as a whole. Since 2013, the Pergamonmuseum has been undergoing staggered renovation work, devised by the Ungers architectural practice, as part of the Master Plan Museumsinsel. During the current stage of renovations, the hall containing the Pergamon Altar is closed since 29 September 2014 and is due to remain closed to the public until 2019. The north wing and the gallery of Hellenistic art are also affected by the closure. The South Wing of the Pergamonmuseum, featuring the Market Gate of Miletus, the Ishtar Gate and Processional Way from Babylon, and the Museum of Islamic Art, remains unaffected and will be open to the public during this time.