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Eiffel Tower, France - Completed in 1889 as a showpiece landmark for that year's World's Fair, the Eiffel Tower in Paris is one of the most recognizable structures in the world. (Photo: Flickr/CC BY-SA 2.0)

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CN Tower, Canada -

Toronto's 1,815-ft (553-m) high concrete communications and observation tower has been piercing the city's skyline since 1976. (Photo: Wikimedia/CC BY 30)

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Leaning Tower of Pisa, Italy - One of the world's most unusual towers, Pisa's tipsy visitor attraction stands off-kilter due to a nearly four-degree lean, the result of an unstable foundation.

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Elizabeth Tower, England - The Palace of Westminster is one of London's most cherished buildings, and its bell tower (often erroneously referred to as Big Ben but, in fact, called the Elizabeth Tower) is one of the city's most photographed structures. (Photo: Flickr/CC BY-SA 2.0)

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One World Trade Center, USA -

Symbolically, New York City's One World Trade Center stands 1,776 ft (541 m) tall—1776 signifying the year the Declaration of Independence was signed. (Photo: Flickr/CC BY 2.0)

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Taipei 101, Taiwan - Inaugurated in 2004 and constructed in the postmodernist architectural style, Taipei 101 is named after the number of floors housed within its characteristic blue-green glass, curtain-walled facade. (Photo: Wikimedia/CC BY-SA 2.0)

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Burj Khalifa, United Arab Emirates -

Resembling a slender oversized dart, Dubai's Burj Khalifa is the tallest structure in the world, an incredible 2,722 ft (829 m) in total.

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Tokyo Skytree, Japan - A broadcasting/observation tower and restaurant, this is the tallest structure in Japan, and the second tallest structure in the world after the Burj Khalifa.

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Petronas Towers, Malaysia - A Kuala Lumpur jaw-dropper, these are the tallest twin towers in the world. Designed by Argentine architect César Pelli, the towers remain a 21st-century cultural icon.

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Belem Tower, Portugal -

A whimsical example of Portugal's unique Manueline architectural style, this limestone bastion was built around 1514 during the so-called Age of Discovery. It's a protected World Heritage Site.

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30 St Mary Axe, England - This Norman Foster-designed City of London head-turner is known as The Gherkin due to its highly unorthodox layout and appearance.

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Oriental Pearl Tower, China - Completed in 1994, this is one of Shanghai's most distinctive landmarks. It features 11 spheres. (Photo: Flickr/CC BY 2.0)

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Peace Tower, Canada - Also known as the Tower of Victory and Peace, this is the centerpiece of Ottawa's Canadian parliament buildings. The tower reaches 302 ft (92 m) in height. (Photo: Flickr/CC BY 2.0)

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Mole Antonelliana, Italy - Turin's landmark eye-opener is not really a tower, but it does house the tallest museum in the world—Museo Nazionale del Cinema. It's also the tallest unreinforced brick building in the world.

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The Shard, England - Diners are seen on the 31st and 32nd floor restaurants of London's Shard tower. 

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Beijing Olympic Tower, China - While it's known as the Olympic Tower, this beautiful and organic-looking structure was, in fact, completed in 2014, six years after the 2008 Summer Olympic Games hosted by the Chinese capital.

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Compton Hill Water Tower, USA - One of three remaining standpipe water towers in St. Louis, Missouri, Compton Hill Water Tower is also one of only seven surviving standpipe water towers in the entire United States. It's a national historic landmark. (Photo: Wikimedia/CC BY 3.0)

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Fat Margaret, Estonia - Tallinn's rotund 16th-century cannon tower is attached to the Old Town's Great Coast Gate. These days housing an engaging museum, the whole structure is part of a UNESCO World Heritage Site.

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Torre Glòries, Spain - French architect Jean Nouvel designed Barcelona's Torre Glòries, which is especially visually dramatic when illuminated at night. (Photo: Wikimedia/CC BY-SA 3.0)

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Rundetaarn, Denmark - Set in the heart of Copenhagen, the Round Tower was built as an astronomical observatory in the 17th century. (Photo: Wikimedia/CC BY-SA 3.0)

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Qutb Minar, India - Qutb Minar is a decorative 239-ft (73-m) tall tapering minaret that forms part of the Qutb complex, a UNESCO World Heritage Site near Delhi.

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Galata Tower, Turkey - Adding considerable allure to the Istanbul skyline is this medieval Romanesque-style stone tower, recognized for its high cone-capped cylinder.

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Canton Tower, China - The form, volume, and structure of this 1,982-ft (604-m) tall multi-purpose observation tower in Guangzhou is formed by two rotating ellipses. (Photo: Flickr/CC BY 2.0)

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N Seoul Tower, South Korea -

Perched on the summit of Namsan Mountain in central Seoul, this communication and observation tower marks the second highest point in the city, with outstanding panorama views to match.

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Pharos of Abusir, Egypt - Located on the shore of Lake Mariout, this hexagonal and cylindrical tower, an ancient tomb thought to be a scaled-down model of the Pharos of Alexandria (a lighthouse), dates back to the reign of Ptolemy II (285–246 BCE). (Photo: Wikimedia/CC BY-SA 3.0)

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Shukhov Tower, Russia - This Moscow broadcasting tower was completed in 1922 during the last days of the Russian Civil War. Closed to the public, the tower—a rare example of Russian avant-garde architecture—is under threat of demolition.

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Al-Muhdhar Mosque, Yemen - Built in 1914 entirely from adobe, Tarim's historic mosque is noted for its 131-ft (40-m) minaret, designed by renowned Yemeni architect Awad Salman Afif al-Tirmi.

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Obelisk of Axum, Ethiopia - Dating back to the 4th century CE, this ornamented granite obelisk, or stele, stands 79-ft (24-m) tall and marks an underground burial chamber.  (Photo: Wikimedia/CC BY 2.5)

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Broadway Tower, England - Standing on Broadway Hill in Worcestershire is this 65-ft (20-m) tower known as a folly. Completed in 1799, it is today a well-known tourist attraction. (Photo: Wikimedia/CC BY 2.5)

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Torre dos Clérigos, Portugal - Designed by Italian architect Nicolau Nasoni, this is the bell tower of the 18th-century Clérigos church. The tower is a cherished symbol of the city of Porto. (Photo: Flickr/CC BY-ND 2.0)

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San Gimignano, Italy - Fourteen towers of varying heights (dating back to the 13th and 14th centuries) endow this already picturesque walled medieval town in Tuscany with a beguiling charm.

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Rajabai Clock Tower, India - Designed by English architect Sir George Gilbert Scott and completed in 1878, Mumbai's Rajabai Clock Tower fuses Venetian and Gothic styles, and stands at a height of 280 ft (85 m).

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Coit Tower, USA - Perched on top of Telegraph Hill in San Francisco, Coit Tower, which dates back to 1933, affords impressive Bay Area views from its observation deck. (Photo: Flickr/CC BY 2.0)

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Three Pagodas, China -

Located north of the old town of Dali are these three pagodas, a trio of tiered towers made of brick and covered with white mud. Dating back to around 823-840 CE, the elegant structures are among the tallest pagodas in China.

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The Round Tower, Ireland - Glendalough in County Wicklow is home to this fine example of an early medieval round tower. (Photo: Flickr/CC BY-NC-ND 2.0)

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Vainakh settlement, Chechenya - An excellent example of Vainakh tower architecture, this ruined medieval settlement features a number of well-preserved structures characterized by square foundations, tapering walls, and pyramidal roofs.(Photo: Wikimedia/CC BY-SA 4.0)

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Svanetian towers, Georgia -

Scattered across Georgia are ruins of tower houses built as defensive structures and known as Svanetian towers.

See also: The 25 most stunning skylines in the world.

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