Portsmouth Square (traditional Chinese: 花園角; simplified Chinese: 花园角; pinyin: Huāyuán jiǎo; Jyutping: Faa1jyun4 Gok3), formerly known as Portsmouth Plaza, and originally known as Plaza de Yerba Buena, or simply La Plaza, is a one-block plaza (57,516 sq ft (5,343.4 m2)) in Chinatown, San Francisco, California. Established in the early 19th century, during the period of Mexican California, the plaza was renamed following the U.S. Conquest of California in honor of the USS Portsmouth, the American ship which captured the city. It is bounded by Kearny Street on the east, Washington Street on the north, Clay Street on the south, and Walter Lum Place on the west.