The Renaissance Center (also known as the GM Renaissance Center and nicknamed the RenCen) is a group of seven interconnected skyscrapers in Downtown Detroit, Michigan, United States. Located on the International Riverfront, the Renaissance Center complex is owned by General Motors as its world headquarters. The central tower, the Detroit Marriott at the Renaissance Center, is the tallest all-hotel skyscraper in the Western Hemisphere, and features the largest rooftop restaurant, Coach Insignia. It has been the tallest building in Michigan since it was erected in 1977.

John Portman was the principal architect for the original design. The first phase constructed a five tower rosette rising from a common base. Four 39-story office towers surround the 73-story hotel rising from a square-shaped podium which includes a shopping center, restaurants, brokerage firms, banks, a four-screen movie theater and private clubs. The first phase officially opened in March 1977. Portman's design renewed attention to city architecture, constructing the world's tallest hotel at the time. Two additional 21-story office towers (known as Tower 500 and Tower 600) opened in 1981. This type of complex has been termed a city within a city.

In 2004, General Motors completed a US$500 million renovation of the Class-A center as its world headquarters, which it had purchased in 1996. The renovation included the addition of the five-story Wintergarden atrium, which provides access to the International Riverfront. Architects for the renovation included Skidmore, Owings & Merrill, Gensler, SmithGroup, and Ghafari Associates. Work continued in and around the complex until 2005. Renaissance Center totals 5,552,000 square feet (515,800 m2) making it one of the world's largest commercial complexes.

en.wikipedia.org/wiki/Renaissance_Center