From the moment it opened as the world’s tallest building in 1973, the building formerly known as the Sears Tower has captured the imaginations of visitors. Even if you’ve stepped out onto the transparent Skydeck, here are a few things you may not know about the towering building.

1. THE SEARS TOWER YOU’VE HEARD OF WAS ACTUALLY NOT THE FIRST.

The record-breaking skyscraper that looms over Chicago’s Wacker Drive was conceived and constructed between 1969 and 1973, a good six decades after the development of Sears, Roebuck & Company’s original headquarters. The Sears Merchandise Building Tower was erected on South Homan Avenue in the Chicago neighborhood of Lawndale, four miles due west of where its successor would eventually break ground. The original tower was a relatively short 15 stories, maxing out at a height of 249 feet.

2. THE SEARS TOWER HASN’T BEEN CALLED “THE SEARS TOWER” SINCE 2009.

If you live outside of Chicago, there’s a fair chance you never got the memo about the landmark skyscraper’s new handle—the Willis Tower—which it acquired upon the transfer of the property to Willis Group Holdings in 2009. Sears had actually lost the naming rights to the building in 2003, but the retailer’s branding stuck around for another six years until Willis slapped its name on the tower.

3. CHICAGOANS TRIED TO CHANGE THE TOWER’S NAME BACK.

Willis Group Holdings probably knew that there would be some resistance to the name change, but the impassioned outcry against dropping the “Sears” was stunning. Shortly after the Sears Tower became the Willis Tower, 90,000 Chicago citizens joined in a digital movement to oppose the change, and a petition to reverse the change piled up 50,000 signatures.

4. SEARS HAS NOT OCCUPIED THE TOWER SINCE 1995.

The tower’s nominal association with the Sears company was actually the final tie to be cut. Following a gradual decline in prosperity during the 1980s, Sears decided to sell the tower in 1988. But unable to find a buyer, Sears borrowed $850 million from AEW Capital Management and insurance company MetLife, essentially using the building as collateral. In 1994, Sears transferred effective control of the tower to its two creditors and vacated the premises by the following year.

5. BEFORE THE TOWER COULD BE BUILT, SEARS HAD TO BUY A STREET.

In order to build the tower, Sears purchased 15 buildings from 100 owners. But more problematic was Quincy Street, which divided the lots the building was going to go up on. Sears paid the city $2.7 million for the road and ripped it out.

6. THE TOWER IS ACTUALLY COMPOSED OF NINE DIFFERENT STRUCTURES.

Unlike fellow giants like the Empire State Building and the World Trade Center, the Sears Tower was actually constructed as a collection of nine separate buildings, planted together in a unifying square. The “tubes” share a uniform width, measuring to 75 feet square, but are diverse in height. Two (the northwest and southeast tubes) ascend to the building’s 50th story; two (northeast and southwest) to its 66th; three (north, south, and east) to its 90th; and two (west and center) to the Sears Tower’s peak on the 108th story.

7. THE DESIGN WAS INSPIRED BY A PACK OF CIGARETTES.

Unsurprisingly, Sears Tower architect Bruce Graham and structural engineer Fazlur Rahman Khan struggled with the question of marrying stability and style in such a massive building and were unsure of how to reach the building’s target height without sacrificing aesthetic appeal. Khan was particularly uncertain that the tube system would yield a sleek-looking skyscraper. As the story goes, during a lunch to discuss these reservations, Graham grabbed a handful of Camel cigarettes from his pocket and displayed the bundled cylinders, each peering out of his fist at different heights, to his partner. The image struck a chord with both men and ensured the utilization of the tube method for the Sears Tower.

8. LAWSUITS ATTEMPTED TO KEEP THE TOWER FROM EXCEEDING 67 STORIES.

The building may have become a Chicago icon, but in its early days it didn’t take long for the Sears Tower to draw public ire. In March 1972, 56 floors already completed, two lawsuits were filed to stop the building from exceeding 67 stories. The suits, filed in the Lake County and Cook County court systems, represented the fear that a supersized skyscraper would disrupt television reception in the surrounding area. Both motions were dismissed, as was a later plea to the FCC to interfere with the Sears Tower’s development.

9. YOU CAN SEE FOUR DIFFERENT STATES FROM THE OBSERVATION DECK.

Weather permitting, the observation deck at the very top of the tower allows for a panoramic view of not only the surrounding Chicago area, but of the Prairie State’s neighbors to the north and east: Wisconsin, Michigan, and Indiana.

10. THE SEARS TOWER’S BATHROOMS ARE THE HIGHEST ABOVE THE GROUND IN THE WESTERN HEMISPHERE.

At 1353 feet above the streets of Chicago, the tower’s Skydeck bathrooms boast the longest climb up from ground level of any lavatories in the Western Hemisphere. That isn’t to say that there aren’t restrooms in America that reach a higher altitude. The Heavenly Mountain Resort of South Lake Tahoe, Calif., for instance, offers a public facility 9000 feet above sea level. However, since said facilities sit comfortably on the terra firma of the mountainous Sierra Nevada, its ground-to-loo distance pales in comparison to that of the tower’s 103rd-story facilities.

11. TWO SPIDER-MAN WANNABES HAVE SCALED THE OUTSIDE OF THE BUILDING.

The first successful external climb of the Sears Tower took place in 1981. Twenty-five-year-old American stuntman Daniel Goodwin, draped in a full body Spider-Man costume, worked his way up using an arsenal of climbing equipment that included suction cups and camming devices. Almost two decades later, French daredevil Alain Robert—known colloquially as “Spider-Man”—set out to up the ante. In August 1999, Robert successfully scaled the Sears Tower via a safety harness and his own bare hands and feet. As neither feat was sanctioned by the local law enforcement, both men were promptly arrested upon reaching their sky-high goal.

12. A BIZARRE CULT ONCE PLOTTED TO DESTROY THE TOWER.

A far more serious threat to the building emerged in 2006. The FBI caught wind of an amateur terrorist collective’s plot to bomb the Sears Tower and apprehended seven Miami-based men before they could pull off the plan. Although the so-called Universal Divine Saviors, or Liberty City Seven, carried no weapons and had no clear ties to their alleged ideological directors in al-Qaeda, they were deemed a legitimate danger. In addition to their proclivity for grand plans of violence, the group was found to embrace a collection of tenets from faiths including Judaism, Christianity, and Islam. What’s more, the Universal Divine Saviors’s standout function was not as a religious organization, but a group for martial arts enthusiasts.

13. THERE WAS A SHORT-LIVED PLAN TO REPAINT THE TOWER SILVER.

For a brief period in 2009, the building entertained a makeover to accompany its rebranding as the Willis Tower. Owners considered swapping its black façade for a silver veneer but quickly decided that the Chicago landmark should only undergo one change at a time.

14. THE SEARS TOWER ONLY LOST ONE TITLE TO THE PETRONAS TOWER.

After a 25-year stint as the tallest building on the face of the planet, the Sears Tower said farewell to its superlative height in 1998, yielding to a new champion in Kuala Lumpur’s newly erected twin Petronas Towers. The architectural duo bested Sears by a good 33 feet, but they couldn’t outshine the Chicago native across the board. Claiming only 88 floors each, the Petronas Towers did not even come close to besting the Sears Tower’s 108-story world record. This record would stand until 2010 when it was topped by the construction of Hong Kong’s 118-story International Commerce Centre and Dubai’s 163-story Burj Khalifa, current holder of the title of World’s Tallest Building.