What is a park?

Note: This post was edited on Jan. 20, 2007. Hotlinked image(s) were removed. Follow the link(s) to the image location(s). The story of this question begins with my husband's comment that Portland, Oregon has the smallest park, "about the size of a tree pit." I was skeptical but a Google search produced numerous descriptions and photographs to prove his point. Mill Ends Park in Portland, Oregon is "the smallest park in the world" according to Wikipedia. The park was unofficially designated as such in 1946 by Dick Fagan who converted an unused light pole hole into this unique park space. The official designation came in 1948. The Portland Parks and Recreation website features a special note about the park: Mill Ends Park has been relocated to downtown Portland while sections of SW Naito undergo construction. In July 2006, the park will be relocated again, permanently, in the median along the parkway, about 7.5 feet from its original location. Mill Ends Park, Portland Oregon Other small parks Chinatown Park in Chinatown, Boston 0.75 acres, part of the designated Kennedy Greenway Paley Park, New York City (4200 square feet)