Developing Economies), SkyDeck, the Sutardja Center for Entrepreneurship and Technology, and the Berkeley Haas Innovation Lab. The campus is also home to the University of California Botanical Garden, one of the most diverse plant collections in the United States, famous for its large number of rare and endangered species, with more than 12,000 individual species. Outside of the Bay Area, the university owns various research laboratories and research forests in both northern and southern Sierra Nevada. Architecture What is considered the historic campus today was the result of the 1898 "International Competition for the Phoebe Hearst Architectural Plan for the University of California", funded by William Randolph Hearst's mother and initially held in the Belgian city of Antwerp; eleven finalists were judged again in San Francisco in 1899. The winner was Frenchman Émile Bénard, who refused to personally supervise the implementation of his plan and the task was subsequently given to architecture professor John Galen Howard. Howard designed over twenty buildings, which set the tone for the campus up until its expansion in the 1950s and 1960s. The structures forming the "classical core" of the campus were built in the Beaux-Arts Classical style, and include Hearst Greek Theatre, Hearst Memorial Mining Building, Doe Memorial Library, California Hall, Wheeler Hall, (Old) Le Conte Hall, Gilman Hall, Haviland Hall, Wellman Hall, Sather Gate, and the Sather Tower (nicknamed "the Campanile" after its architectural inspiration, St Mark's Campanile in Venice), the tallest university clock tower in the United States. Buildings he regarded as temporary, nonacademic, or not particularly "serious" were designed in shingle or Collegiate Gothic styles; examples of these are North Gate Hall, Dwinelle Annex, and Stephens Hall. Many of Howard's designs are recognized California Historical Landmarks and are listed on the National Register of Historic Places. Built in 1873 in a Victorian Second-Empire-style, South Hall, designed by David Farquharson, is the oldest university building in California. It, and the Frederick Law Olmsted-designed Piedmont Avenue east of the main campus, are two of the only surviving examples of the nineteenth-century campus. Other notable architects and firms whose work can be found in the campus and surrounding area are Bernard Maybeck (Faculty Club); Julia Morgan (Hearst Women's Gymnasium and Julia Morgan Hall); William Wurster (Stern Hall); Moore Ruble Yudell (Haas School of Business); Tod Williams Billie Tsien Architects (C.V. Starr East Asian Library), and Diller Scofidio + Renfro (Berkeley Art Museum and Pacific