a complete rebuilding from bridge to bridge, referring to the area between the Ambassador Bridge, that connects Detroit to Windsor, Ontario, and the MacArthur Bridge, which connects the city with Belle Isle Park. The Detroit Renaissance announced the first phase of construction in 1971, receiving primary financing from the Ford Motor Company. It soon became the world's largest private development with an anticipated 1971 cost of $500 million. The principal architect was John Portman, the architect behind the Westin Peachtree Plaza Hotel and the Peachtree Center in Atlanta, Georgia; the Embarcadero Center in San Francisco, California; and the Bonaventure Hotel in Los Angeles, California. The city within a city arose. The first phase of Renaissance Center opened on July 1, 1976. For phase I, the facade of the first five towers was covered with of glass, and used about of concrete. This did not include the additional glass used for the atriums. It also cost $337 million to construct, employing 7,000 workers. The heating and cooling systems for the buildings were housed in two-story concrete berms facing Jefferson Avenue. Other phases that included residences, additional office and retail space were never constructed. When the Renaissance Center opened, the cylindrical central tower was originally the flagship of Westin Hotels. The top three floors of the hotel hosted an upscale restaurant, The Summit, that rotated to allow a 360 degree view. The shopping center in the podium originally housed high-end boutiques, but now contains a greater complement of restaurants in the retail mix. In 1977, managed by Western International Hotels, the central hotel tower of the Renaissance Center opened as the Detroit Plaza Hotel. It became the world's tallest all-hotel skyscraper surpassing its architectural twin, the Westin Peachtree Plaza Hotel in Atlanta. The hotel was later renamed The Westin Hotel Renaissance Center Detroit. In 1986, it was surpassed in height by The Westin Stamford in Singapore. Since, the Renaissance Center's central tower has held the distinction as the tallest all-hotel skyscraper in the Western Hemisphere. On April 15, 1977, Henry Ford II and Detroit mayor Coleman Young unveiled a plaque commemorating the private investors whose funds made the project possible. Later that evening, 650 business and society leaders attended a benefit to celebrate the Renaissance Center's formal dedication. The money raised from the $300-per-couple tickets went to the Detroit Symphony Orchestra. In 1980, Detroit hosted the Republican National Convention, during this event