United Nations Plaza was built in 1975 as part of the Market Street Reconstruction Project in conjunction with the subterranean installation of BART. United Nations Plaza is a 2.6-acre pedestrian mall extending from Market Street to Hyde Street in San Francisco???s Civic Center area. The plaza is a major portal for all modes of San Francisco???s transportation system including Muni and BART. World-renowned landscape architect Lawrence Halprin was the original plaza designer.