Not for the faint of heart, the Blackstone Group is planning on expanding the Skydeck, the popular observatory on the 103rd floor of the Willis Tower, according to Chicago Business. The skyscraper, still commonly referred to as the Sears Tower, was the tallest building in the world for nearly 25 years before being overbuilt by the Petronas Towers. The new owners acquired the space in 2015 for $1.3 billion, the highest price every paid for a US property outside of New York City, and are considering ways to further develop the property. 

In 2009, the building then held by London-based insurance broker Willis Group, added retractable glass balconies. This panic-inducing attraction extends approximately 4 feet out into the sky, allowing those who dare the ability to stand 1,353 feet in the sky from a glass box referred to as The Ledge. Building on this popular attraction, the fresh proprietors of the tower are considering a $20 million expansion. With glass-bottomed attractions popping up across the country, one of the potential developments would allow visitors to rappel from the 103rd floor. For those who find this terrifying, it probably won't assure you that the descent would remain within a two-story enclosed glass box allowing the visitor to rappel from the 103rd floor to the 102nd. Another idea, already dubbed the Ledgewalk, would offer visitors an opportunity to stretch their legs and breathe in some fresh air on an outdoor glass ledge all the while clipped into a safety harness. 

This is part of a larger 546-million dollar renovation of the property. Jon Gray, Blackstone's global head of real estate, said "The Willis Tower has been under-managed and under-invested in for a number of years." The group plans to boost the property's income by transforming its lower floors into a retail destination/food hall and revamping its office space. The Skydeck, as one of Chicago's main tourist destinations, is poised to be key in attracting new income for the tower.