The tallest building in the world is the Burj Khalifa in Dubai, but the United States boasts plenty of vertical treasures worth marveling at -- especially on Skyscraper Day, Sept. 3, the birthday of architect Louis Sullivan, whose work in the 1890s helped make today's structures possible. Here are the 20 tallest buildings in America, according to the nonprofit Council on Tall Buildings and Urban Habitat, based on height from the "lowest, significant, open-air, pedestrian entrance to the architectural top of the building, including spires." Some of these buildings share their views with the public, and there are deals and budget-friendly tips to alleviate occasionally pricey admission fees. But skyscrapers can inspire just as much awe when seen from street level.
Height: 974 feet
The 57-story Comcast Center tower has a few distinctive features, including a 2,000-square-foot HD video wall in the lobby showing hyper-realistic images. A bright, open (and open to the public) eight-story winter garden uses sunscreens and louvers to bring in maximum daylight while blocking the sun's heat, part of the building's overall ecological focus.
Height: 977 feet
Part of the new World Trade Center complex in New York City, 4 World Trade Center contains 65 floors of office and retail space. Visitors to the Freedom Tower and 9/11 Memorial can take a short stroll to check out the modern, minimalist structure with an expansive ground-floor lobby, but the 57th-floor terrace is now owned by a finance tech company.
Height: 992 feet
The gleaming, reflective structure of the Wells Fargo Plaza greets visitors to downtown Houston. Its 71 stories contain primarily office suites, a health club, and the Consulate-General of the United Kingdom.
Height: 995 feet
Two Prudential Plaza is flanked by the Aon Center and One Prudential Plaza in the Chicago's Loop. Sixty-four stories tall, it features a pyramid peak with distinctive chevron detailing on the sides.
Height: 1,002 feet
At 75 stories, the JPMorgan Chase Tower is the tallest building in Texas, but what really sets it apart is that it's the tallest five-sided building in the world. The 60th-floor observatory, formerly a top free tourist attraction for Houston visitors, was closed to the public in June.
Height: 1,004 feet
One57, in midtown Manhattan overlooking Central Park, boasts some of the most expensive residences in New York City -- including a penthouse that sold for $101 million in 2015. The 75-story tower is easily recognized for its gleaming, wavy, blue glass, in addition to its height.
Height: 1,007 feet
Downtown Chicago's Franklin Center, home to offices and commercial space, is clad in dark red and rose-colored granite in a postmodern style that features sharp pinnacles, bold lines, and Gothic detailing reminiscent of the 1920s. The tower rises 60 stories.
Height: 1,018 feet
To see Los Angeles in all its glitzy glory, head to the tallest building in California. The 73-story U.S. Bank Tower offers an open-air observation deck and the Skyslide -- an all-glass slide for visitors who aren't scared of feeling like they're falling 45 feet while suspended 1,000 feet above city streets. A combo ticket costs $33 for adults; subtract the Skyslide and adults pay $25 for general admission to OUE Skyspace LA.
Height: 1,023 feet
The tallest building in the Southeast, the 55-story Bank of America Plaza features two landscaped plazas on either side where visitors can admire the Art Deco tower. The spired top lights up golden at night.
Height: 1,046 feet
The New York Times Building sits a block from Times Square in New York City. The 52-story building boasts double layers of floor-to-ceiling glass walls, so the sun serves as a major source of light for its occupants.
Height: 1,046 feet
The 77-story Chrysler Building in midtown Manhattan is a must-see for its Art Deco architecture, featuring a beautiful crown and majestic spire -- put up by surprise in 1930 to successfully make the building the world's tallest, although the honor lasted for only 11 months. A 71st-floor viewing gallery was closed to the public in 1945, but visitors should keep an eye out for this quintessential New York structure and its gargoyles when walking up Lexington Avenue.
Height: 1,118 feet
Formerly known as the Condé Nast building, 4 Times Square is home to the H&M clothing chain's biggest store (and giant, branded skyline signs) and provides more than 1 million square feet of office space on its 48 floors. It's lauded as one of the biggest structures built to be environmentally responsible, using recycling chutes, solar technology, and fuel cells.
Height: 1,128 feet
The 360 Chicago observatory on the 94th floor of the John Hancock Center features an attraction called Tilt, which literally tilts visitors to a 30-degree angle so they can look down onto Michigan Avenue. Admission is $18 for adults and $12 for kids, but there's a 10 percent discount when buying online. Another option: Visit the Signature Lounge, on the 96th floor of this 100-story tower, where a beer costs less than observatory admission but offers the same view (minus the tilt).
Height: 1,136 feet
The 83-story Aon Center was previously known as the Standard Oil Building, the world's tallest marble-covered building at its completion in 1974. The marble was later removed due to cracks and instability, but the Aon Center, now Chicago's third-tallest structure and covered in white granite, is still a sight to behold.
Height: 1,200 feet
Opposite Bryant Park, the Bank of America Tower stands 55 stories. It houses more than 2 million square feet of office space and is renowned for its green architecture, including an Urban Garden Room on the ground floor with living plant sculptures that's free to visit.
Height: 1,250 feet
This treasure of midtown Manhattan needs no introduction. Unfortunately the prices are as high as the spire. Tickets to the main deck on the 86th floor cost $32 for adults; a pass that includes admission to the deck on the 102nd story (the building's highest) costs $52. Children's ticket prices are $26 and $46, respectively.
Height: 1,389 feet
This gleaming part-condo, part-commercial tower with hotel rooms, three restaurants, and a spa was designed to fit in with Chicago's existing skyline, with each of its three "steps" matching the height of nearby buildings. Despite being one of the tallest in the country, at 98 stories, the building offers only one way for the public to take in a view: an outdoor restaurant on the 16th floor -- so, less than a fifth of the way up.
Height: 1,396 feet
To see the tallest residential building in the world, head to Park Avenue and East 56th Street in New York, where 432 Park Avenue holds 104 condominiums. The 85-story tower is taller than the Empire State Building, but to see the view, you have to know someone on the inside.
Height: 1,451 feet
The Willis Tower (formerly the Sears Tower) is 108 stories, but its Skydeck Observatory and famous glass-bottom balconies are on the 103rd floor. Visitors get views of the Chicago area and Lake Michigan and, on a clear day, even a peek at Indiana, Wisconsin, and Michigan. Admission is $22 for adults and $14 for kids, but a Travelzoo deal gets adult visitors in for $17.
Height: 1,776 feet
With 104 stories rising a symbolic 1,776 feet, One World Trade Center has officially been the tallest skyscraper in America since its completion in 2012. The One World Observatory on floors 100 to 102 of the tower offer panoramic views of Manhattan, Brooklyn, and New Jersey starting at $34 for adults and $28 for children. There are online deals of 20 percent off for MasterCard holders on Mondays and Century 21 department store customers on weekdays. Eat before heading up, though. Food at the observatory's three eateries is both expensive (a burger starts at $20) and poorly reviewed.