City National Plaza is a twin tower skyscraper complex on South Flower Street in western Downtown Los Angeles, California, United States. It was originally named ARCO Plaza upon opening in 1972. History Richfield Tower The present complex is on the site of the landmark Richfield Tower, that was designed in the Art Deco style by Morgan, Walls & Clements, and completed in 1929. It was the headquarters of the Atlantic Richfield oil company. It was demolished in the spring of 1969. ARCO Plaza The current skyscraper complex was built as the ARCO Plaza, with a pair of 52-story office towers. One became the new world headquarters for the Atlantic Richfield Company (ARCO), the present day Paul Hastings Tower. An underground shopping complex was accessed by open escalators from the street level plaza. Upon completion in 1972, the ARCO Plaza towers were the tallest buildings in the city for one year before being overtaken by Aon Center, and were the tallest twin towers in the world until the completion of the World Trade Center in New York City. The towers are the tallest twin buildings in the United States outside of New York City, where the 55-floor Time Warner Center stands at . In 1986, joint owners ARCO and Bank of America sold the buildings to Shuwa Investments Corp., the American subsidiary of Shuwa Co. of Tokyo, for $650 million while both remained tenants in their respective named towers. Shuwa later sold the property in 2003 to Thomas Properties Group and other investors for $270 million. The towers are constructed of steel frames covered with polished panels of forest green granite and panes of bronze glass. In 2016, the exterior of the top two floors and the service roof of The Paul Hastings Tower were modified on the north, east, and south flanks to house their upgraded headquarters and offices. This modification features silver trim and panes of light green glass panels. City National Plaza The ARCO Plaza complex was renamed City National Plaza in 2005, and the south and north towers, respectively, were renamed City National Tower and Paul Hastings Tower. The low-rise building at the back of the plaza is known as the Jewel Box, and is occupied by the Gensler architectural firm. Gensler moved from Santa Monica to the Jewel Box in 2011. The plaza includes a monumental sculpture-fountain, Double Ascension by artist Herbert Bayer. Tenants "Jewel Box"