321 North Clark at Riverfront Plaza is a 35-story, 155.45 m skyscraper constructed from 1983 to 1987 in Chicago, Illinois. The tower was built by BCE Development Properties and designed by Skidmore, Owings & Merrill as part of the Riverfront Plaza development on the north bank of the Chicago River. 321 North Clark opened in April 1987 and was named "city development of the year" by the Chicago Sun-Times.