Willis Tower has been a defining feature of Chicago’s skyline since the early 1970s, when it rose above the city as the tallest building in the world—a title it held for nearly a quarter of a century. Even now, decades after its completion, the 1,450-foot structure remains one of the most recognizable symbols of the city, its stepped silhouette instantly familiar to anyone who has seen the downtown core from a distance. The tower was originally built as the headquarters for Sears, Roebuck & Co., a retail giant that needed space for thousands of employees in a single location. At the time, the idea of a single company occupying an entire skyscraper was ambitious, and the building’s scale reflected both the company’s confidence and the architectural possibilities of the era.
The design was revolutionary, conceived by structural engineer Fazlur Rahman Khan and architect Bruce Graham. Instead of relying on a single central core, they created a bundle of nine square tubes, each functioning as an independent structural element. Some of these tubes terminate at different heights, giving the building its distinctive tiered appearance while maintaining stability. This innovation, known as the "bundled tube" system, became a model for high-rise construction worldwide, allowing for greater height without sacrificing strength. The approach was both practical and elegant, solving the problem of wind resistance in a city where gusts off Lake Michigan can be fierce.
Visitors who make the trip to the Skydeck on the 103rd floor are rewarded with one of the most expansive views in the Midwest. On clear days, the horizon stretches far enough to glimpse four states—Illinois, Indiana, Michigan, and Wisconsin—though haze often softens the edges of the landscape in summer. Winter brings sharper visibility, with the city’s grid of streets and the frozen expanse of Lake Michigan laid out below. The experience is heightened by The Ledge, a series of glass balconies that extend slightly from the building’s facade. Standing on one feels like hovering in midair, an illusion reinforced by the sheer drop beneath your feet. The sensation is exactly as unsettling as you’d expect, though the engineering is sound—these boxes are designed to support several tons of weight.
The tower’s height comes with its own set of quirks. On windy days, the upper floors sway noticeably, shifting by several inches in either direction. Engineers insist this is normal, a necessary flexibility to prevent structural stress, but it’s still disconcerting to feel the building move beneath you. Elevators may run slower during particularly strong gusts, a small concession to the forces at play. The movement is most apparent in the Skydeck, where the lack of surrounding structures makes the sensation more pronounced. It’s a reminder that even the most solid-seeming skyscrapers are designed to bend, not break.
Access to the Skydeck is managed through timed entry tickets, and the security line at the base can stretch longer than expected, especially during peak hours. Evening visits are pricier, but the view at sunset justifies the cost—the city’s lights flicker to life as the sky shifts from gold to deep blue, and the lake reflects the last traces of daylight. The lower levels of the tower house a small exhibit on the building’s construction and the evolution of Chicago’s skyline, offering context for the engineering marvel overhead. The entrance to the Skydeck is separate from the main office lobby, located on Jackson Boulevard, so visitors don’t have to navigate through the building’s daily business operations.
Willis Tower is more than just an observation deck, though. It remains a working office building, home to law firms, financial companies, and other businesses that keep the elevators busy throughout the day. The contrast between the tower’s public and private functions is striking—one moment, you’re standing in a glass box hundreds of feet above the street, and the next, you’re back in the quiet efficiency of an office corridor. The building’s dual identity is part of what makes it interesting: it’s both a monument to human ambition and a functional part of the city’s daily life.
Weather plays a bigger role in the experience than most visitors anticipate. On particularly windy days, The Ledge may be closed for safety, a precaution that’s announced at the ticket counter. Even when the balconies are open, the wind can make the glass feel less secure than it is, though the sensation is more psychological than real. The building’s height also means that conditions at the top can differ dramatically from those at street level—what feels like a mild breeze below might be a stiff gust up above. It’s one of the reasons the view changes so much from season to season, with winter’s crisp air offering the clearest vistas and summer’s humidity sometimes obscuring the horizon entirely.
For all its height and engineering prowess, Willis Tower doesn’t feel like a sterile monument. It’s a living part of Chicago, one that has witnessed the city’s transformations over the past fifty years. The offices inside have housed countless meetings, the elevators have carried generations of workers, and the Skydeck has framed the city’s growth for millions of visitors. It’s a place where the past and present coexist—the ambition of the 1970s meets the realities of modern urban life. Whether you’re there for the view, the history, or just the thrill of standing on a glass ledge, the tower offers a perspective that’s hard to find anywhere else.
