The Most Vertigo-Inducing Observation Decks On The Planet

Skyscraper observation decks can give you the feeling of walking on air as well as an appreciation for the engineering brains required to construct such tall buildings. Some buildings now offer experiences like walking hands-free on a ledge. And these decks aren't just urban look-outs—some observation decks constructed in national parks allow you to get in touch with nature in a whole new way.

Formerly the Sears Tower, Willis is the second tallest building in the Western Hemisphere. On its 103rd floor (of 110) is the Skydeck, which offers spectacular views of Chicago and up to 50 miles in each direction (you may remember it from the scene in "Ferris Bueller's Day Off"). To really get your heart pounding, though, you can step out onto the Ledge, a glass balcony that extends 4.3 feet out from the Skydeck—you'll be looking 1,353 feet down onto Wacker Drive and the Chicago River.

Get an adrenaline-inducing view of one of the world's Seven Natural Wonders on the Skywalk at Eagle Point, a glass bridge that extends 70 feet out over the rim of the Grand Canyon. If you look down, you'll be staring 4,000 feet down to the floor of the Canyon below.

Located in the One World Trade Center, which was built on the northwest corner of the site where the former World Trade Center towers stood before they were destroyed in the 9/11 attacks, the One World Observatory opened in 2015. The building was intentionally created to stand at 1,776 feet to commemorate the year of U.S. independence, and it officially passed up the Willis Tower as the tallest building in the Western Hemisphere. On the 100th floor, you can take in panoramic views of Manhattan, Brooklyn, New Jersey and the surrounding waters.

Rising from the desert of U.A.E., Burj Khalifa is officially the tallest building in the world—it stands at more than 2,700 feet and has 160 habitable stories. From either the 125th or 148th level, you can take in the views from the highest outdoor observatory in the world.

The CN Tower, a signature icon of Toronto's skyline, held the title of "world's tallest tower" and "world's tallest free-standing structure" for 34 years, until Dubai's Burj Khalifa and China's Canton Tower were built in 2010. It offers a unique experience for altitude-seeking visitors: You can take a hands-free, 30-minute walk on a 5-foot-wide ledge surrounding the top of the tower, 116 stories up (while attached via a harness to a safety rail overhead). For those looking for a little less excitement, you can stay inside on the tower's LookOut Level for beautiful views, or walk across the tower's glass floor.

Within Jasper National Park, you can now gain a bird's-eye view of the Sunwapta Valley when you look 918 feet down through the glass-bottomed walkway to the cliffs below. You can view the Canadian Rockies, waterfalls, wildlife and glaciers from the cliff-edge, 0.6-mile-long walkway.

Translated as "Step Into the Void," daring visitors can step into an enclosed glass box that has reportedly more than 3,200 feet of free air below it. The scenery is stunning—if you get past the fear, the look-out (as well as the other terraces at Aiguille du Midi) allows you to admire the Bossons Glacier plus the French, Swiss and Italian Alps, as well as the famous Mont Blanc.

The 101-story Shanghai World Financial Center houses multiple options for viewing opportunities on different floors, including an extensive view of Shanghai along the Huangpu River, and a Sky Walk on the 100th floor—a 180-foot corridor made of glass, from which you can view the top of the Oriental Pearl Tower and feel as if you're walking on top of the Jinmao Building.

Much like the CN Tower in Toronto, you can take a hands-free walk outside around the top of the 1,076-foot-tall Sky Tower on New Zealand's North Island. But true thrill-seekers can take it a step further by base jumping off the tower by a controlled-descent wire to fall 630 feet.

In the 88-story, 1,482-foot twin-tower structure, you can take an elevator up to the Skybridge, a connecting structure between the towers and the world's highest two-story bridge, then ascend another elevator in the second tower to the 86th level, where you can take in picturesque views of Kuala Lumpur.