Among them are the remains of John Frederick, Duke of Brunswick-Luneburg, his daughter Anna Sophie (1670–1672), Ernest Augustus, Elector of Brunswick-Luneburg and his wife Sophia of the Palatinate, their younger son Ernest Augustus, Duke of York and Albany and Princess Charlotte of Clarence (1819–1819), daughter of William IV of the United Kingdom. In front of the mausoleum are the graves of Ernest Augustus, Duke of Brunswick and his wife Princess Viktoria Luise of Prussia. The year 2000 saw the completion of a brand new "Rainforest-house" ("Regenwaldhaus"), partially as a replacement for the legendary Palmenhaus (which was demolished in 1950) and partially for the Expo 2000. Inside is a tropical landscape containing more than plants - different species of tropical butterflies and birds were also incorporated into the environment. Further exhibits of the building include several displays themed gardens. The Welfengarten (Welf Garden) makes up the grounds of the University of Hannover, as the university now uses the gothic revival castle at the garden's centre - Welfenschloss - as its main building. Its construction began in 1857, however, before it was completed, Hanover was annexed by Prussia in 1866. In the following years the building was accomplished in its present form. In front of the building is a bronze sculpture of the "Lower Saxony Steed" ("Niedersachsenross") – the heraldic animal found on the coat of arms of Lower Saxony. The Welfengarten, like the other gardens, was also destroyed during the Second World War, but it was rebuilt specifically as the campus of the university. Although the University has occupied the castle since 1879, it was not until 1961 that Prince Ernest Augustus of Hanover sold the Welfengarten to the city of Hanover. He kept however the "Princely House" (Fürstenhaus), located near the Great Garden and built by king George I of Great Britain for his daughter Anna Louise in 1720, for himself. His grandson Prince Ernst August of Hanover uses it as his private residence today. The museum in this small palace, with an elaborate furniture collection, has therefore been closed.