Observation decks on really tall buildings are certainly nothing new. Many of the world’s most famous skyscrapers have them — the Petronas Twin Towers in Kuala Lumpur, Malaysia are actually connected by the SkyBridge, allowing visitors to walk between the two gigantic twin structures. But these six skyscrapers take the whole observation deck experiences a step further with glass-bottomed viewing platforms. Because if being hundreds of feet above the ground wasn’t terrifying enough, now you can stare down into the abyss and hope that the floor holds (we promise it will).
Lotte World Tower Observation Deck — Seoul, South Korea

Photo: leungchopan/Shutterstock
The Observatory at the Shanghai World Financial Center — Shanghai, China

Photo: chuyuss/Shutterstock
CN Tower — Toronto, Ontario, Canada

Photo: Inga Locmele/Shutterstock
Tokyo Skytree — Tokyo, Japan

Photo: shinnji/Shutterstock
The Edge at Eureka Skydeck 88 — Melbourne, Australia

Photo: RHIdefined
Sky Tower — Auckland, New Zealand

Photo: SkyTower
Sky Tower’s glass-bottomed observation deck is the most nerve-wracking of any down south. The straight-down views can be overwhelming, but the building’s planners anticipated this and installed touch-screen monitors equipped with cameras to explain what exactly it is you’re looking at, if you need some help orienting yourself post-vertigo attack.
Skydeck at the Willis Tower — Chicago, Illinois

Photo: Skydeck Chicago
Chicago offers multiple high-up options for taking in the city’s skyline, but none scarier than Skydeck at the Willis Tower. The Ledge and its glass bottom protrude four feet beyond the building’s 103rd floor, providing views across four states at once.