Inaugurated in 1968, it is an eye catcher for its huge X's. Rather than being a mere aesthetic quirk, these are the reinforcements that help the construction resist wind loads and downsize internal columns. The "trussed tube system" invented by the engineer, Fazlur Khan, in the early 1960s was a fundamental step toward building unprecedented high towers. It houses residential apartments, commercial spaces, offices, a panoramic restaurant, and an observatory on the 94th floor with 360-degree views of the city.
Aon Center
Chicago's fourth tallest building at 83 stories and 346 meters high looms at 200 East Randolph Street. Its soaring white rectangle with vertical stripes brings a splash of color to the city's skyline. Designed by the architect, Edward Durell Stone, known for his formal and decorative modernism, the building was completed in 1973 on behalf of the Standard Oil Building. The company wanted a monumental headquarters that lived up to its ambitions. Originally, many columns of the building were clad in white Carrara marble. However, such an aesthetically unique material is not so resistant to the wild temperature range of Chicago's climate. Therefore, the entire building was covered in sturdy granite in the 1990s. The Carrara marble was turned into trophies for the staff.
Marina City
This residential complex overlooks the North Bank at 300 North State Street. Designed by the architect, Bertrand Goldberg, it was built between 1959 and 1964. Those seeing it for the first time are attracted by the round, angle-free geometric shapes of the two towers that are so different from everything around it—first of all the essential, vigorous, and efficient IBM Building with its 212 meters of black anodized aluminum. Marina City, with its characteristic “corncob towers”, was built with the idea of creating an urban oasis of where to live, have fun, and work. The mid-1900s families were looking for comfort, convenience, and space outside of city limits. Architect Bertrand Goldberg intended to slow down the urban exodus by making it beautiful to live in the center. Besides the 65 residential floors, Marina City's amenities of 1967 included a theater, gymnasium, swimming pool, ice skating rink, bowling alley, 19-story garage, shops, restaurants, laundry with a city view, and an open-air terrace on top of each building.
Aqua Tower
The white concrete, the curved balconies, and the stained glass create the impression of a water cascade flowing down the sides of the building. It is a tribute to Lake Michigan and the natural morphology of the Windy City by the star of contemporary architecture, Jeanne Gang, founder and partner of the Studio Gang. This woman can boast of having designed the third tallest building in Chicago, i.e., the brand new Vista Tower. Seen as a whole, it appears as a vertical landscape made up of hills, valleys, and pools. Each balcony is unique in size, shape, and overhang, allowing residents to connect with neighbors on the floors below and above. This reflects the Gang's community ideal. However, it also has a functional aspect. In fact, the balconies break the whirlwinds rushing through the sky.
Wrigley Building
The dazzling Wrigley Building, one of the city's oldest, most iconic buildings stands at 400 North Michigan Avenue, a few meters northwest of the Chicago River Bridge. Built between 1920 and 1922 by the greatest architectural firm of the time, Graham, Anderson, Probst & White, for the chewing gum magnate, William Wrigley Jr., it is close to celebrating its first century of life. Every inhabitant and visitor are familiar with its 2-towered structure at least by sight, because it is located in the beating heart of the Magnificent Mile, the city's commercial area. The six different shades of white of its 250,000 tiles, more and more sparkling as the skyscraper rises, create a glow that makes them stand out in the light of the sky against all other buildings. The façade is illuminated at night by more than a hundred 1000 watt lamps. Another distinctive element is the reference to the “Giralda”, the Cathedral of Seville's bell tower in Spain. On top of the southern building stands the clock tower, Chicago's "Big Ben".