Recognized by international art critics as a world-class museum in the heart of the Midwest, the Des Moines Art Center has amassed an important collection with a major emphasis on contemporary art. The collection’s overriding principle is a representation of artists from the nineteenth century to the present, each through a seminal work. This accounts for an impressive collection that ranges from Edward Hopper’s "Automat"​ to Jasper Johns’ "Tennyson,"​ Henri Matisse’s "Woman in White,"​ Georgia O’Keeffe’s "From the Lake No. 1,"​ Francis Bacon’s "Study after Velásquez’s Portrait of Pope Innocent X,"​ Bill Viola’s "Ascension,"​ and Cecily "Brown’s Half-Bind."​ The Art Center’s physical complex marries with the collection for a totally integrated experience. The collection is housed in three major buildings, each designed by a world-renowned architect—Eliel Saarinen, I. M. Pei, and Richard Meier. With the exception of special events, admission to the museum is free. In September 2009, the John and Mary Pappajohn Sculpture Park opened in Des Moines’ Western Gateway Park. Philanthropists John and Mary Pappajohn have provided funding for and donated 28 sculptures by internationally acclaimed contemporary artists to the Des Moines Art Center. The collection of sculptures by such artists as Louise Bourgeois, Deborah Butterfield, Willem de Kooning, Olafur Eliasson, Keith Haring, Ellsworth Kelly, Jaume Plensa, Richard Serra, Joel Shapiro, and Mark di Suvero, is the most significant donation of artwork to the Art Center in a single gift in the museum’s history. The Pappajohn Sculpture Park is a collaboration of the Pappajohns, the City of Des Moines, the Des Moines Art Center, and numerous corporate and private donors.