The Solomon R. Guggenheim Foundation, established in 1937, operates the Solomon R. Guggenheim Museum on Fifth Avenue in Manhattan's Museum Mile, overlooking Central Park. The museum opened in 1939 as the Museum of Non-Objective Painting under founding director Hilla von Rebay and took its current name in 1952, three years after Solomon R. Guggenheim's death. Its landmark building, the only museum designed by Frank Lloyd Wright, is known for a spiral ramp encircling a six-story gallery. The foundation's collection holds roughly 8,000 works of Impressionist, Post-Impressionist, modern, and contemporary art, and it also operates sister museums in Bilbao and Venice.