The Renaissance Center in downtown Detroit, Michigan, United States

The Renaissance Center, commonly known as the RenCen, is a complex of seven connected skyscrapers in downtown Detroit, Michigan, United States. The Renaissance Center complex is on the Detroit International Riverfront and is owned and used by General Motors as its world headquarters. The central tower has been the tallest building in Michigan since its completion in 1977. John Portman was the principal architect for the concept design, with the complex seeming to be an aesthetically architectural sibling of the Westin Bonaventure Hotel in California completed a year earlier. The first phase consisted of a five-tower rosette rising from a common base. Four 39-story office towers surround the 73-story hotel rising from a square podium that includes a shopping center, restaurants, brokers, and banks. The first phase officially opened in March 1977. Portman's design brought renewed attention to city architecture since it resulted in the construction of the world's tallest hotel at the time. Two add