Yunyan Pagoda, China

Many consider the Leaning Tower of Pisa one of the world's architectural wonders, but it's not the only famously tilting structure in the world. Around the globe, there are other stunning slanted spires and tottering towers. Many of these famous inclines were Mother Nature's doing -- a result of an earthquake or a nearby sinkhole -- and while officials have taken measures to stabilize some of their leaning monuments, all of them are still vulnerable to weather's effects. The Tower ofPisa underwent a decade-long stabilization project(recently declared successful), and even London's Big Ben has been found to have developed a tilt, gradually settling into the land on which it is built, according to the Telegraph.

"Foundations for structures built on unstable soils can be susceptible to wet or dry extremes, which can lead to additional sinking," says Weather.com meteorologist Chris Dolce. In the following pages, we take a look at the world's leaning towers, and how nature (and in some case, man) was responsible for their precarious positions.

Located in Suzhou, China, Yunyan Pagoda, also known as the Tiger Hill Pagoda, has been referred to as the "Leaning Tower of China" due to its famous tilt. The 154-ft , seven-story pagoda has balconies at every level and was built to resemble the wooden-structured pagodas of the time.Due to the forces of nature and because the foundation was built from rock and soil, the Yunyan Pagoda has been tilting since the Ming Dynasty (1368-1644). It now leans roughly three degrees due to the cracks in two supporting columns, according to an article by O.G. Ingles in the Australia Journal of Chinese Affairs. In the 50s, the base of the pagoda was reinforced and concrete was pumped into the soil to form a more stable foundation. During the process, a stone container holding Buddhist scriptures was uncovered and dated the tower's construction to 961 A.D., according to Andrew Forbes' "National Geographic Traveler: Shanghai."

Leaning Tower of Nevyansk, Russia

There's still some debate over the exact purpose of the Nevyansk Tower in Russia, built around 1732 on the orders of Russian industrialist Akinfiy Demidov. Some say that Demidov used it as a "bank safe", others believe it was either a watchtower, or a belltower, or a prison, according to Ekaterinburg.com. According to legend, the 189-ft tower, which leans about 3 degrees, was purposely inclined southwest to face Demidov's birthplace, but restorers claim that there is no evidence the tower was built purposely inclined.The soil on which the tower was built was eroded by ground waters, and could not withstand the multi-ton pressure of the footing, according to the Russian Cultural Heritage website. The tower began to tilt and finally became lopsided and in order to straighten the construction, the architects trimmed the bricks at a certain angle, giving the building its sable-like shape.

Leaning Tower of Pisa, Italy

A tourist takes a photo at sunrise on May 8, 2011, of the leaning tower of Pisa in an empty square. (Fabio Muzzi/AFP/Getty Images)

The most famous of all tilting towers, Italy's Leaning Tower of Pisa was constructed over 199 years. Since 1173, the 183-ft, eight-story bell tower (or campanile) has defied gravity and withstood the elements, war, and restoration schemes and has lured visitors by the thousands, making it one of Italy's most popular tourist attractions. The tower sits on an unstable subsoil made up of soft estuarine deposits of sandy and clayey silts laid down under tidal conditions tens of thousands of years ago, according to Nicholas Shrady's "Tilt: A Skewed History of the Tower of Pisa." Pisa is practically a bog and only long breaks during the period of the tower's construction (1173 to 1370) -- which allowed the underlying earth to compact itself and gradually adapt to the structure's weight -- prevented it from collapsing completely, according to the Telegraph.

From 1990 to 2010, the tower was closed to the public because of safety issues and a team of experts and engineers implemented a $40 million project to stabilize the structure. The work involved extracting some 77 tons of earth from the northern sideto encourage the tower to right itself, according to BBC News.According to an annual report released by the official surveillance group tasked with monitoring the project, the tower, which has reached a tilt of 15 feet in 1989, has recovered roughly 2.5 centimeters (almost one inch) of its vertical incline between 2001 and 2013. The tower had now returned to its position it was in before 1838, and figures reveal that it didn't move at all between 2003 and 2009, reported the Telegraph. The committee overseeing the project announced that the tower should remain safe for another 200 years.

Leaning Tower of Suurhusen, Germany

Until 2010, the Leaning Tower of Suurhusenin northwestern Germany, which leans at an angle of about 5.19 degrees, was the most tilted tower in the world, according to the Guinness Book of World Records. The church was actually built in the middle of the 13th century but a 90-ft tower was added in 1450.The tower was built on wooden foundations and the combination of the oak wood foundations and wet soil has caused the tower to slowly lean to one side over the years, according to the Daily Mail. Since the early 1980s, villagers have been successful in carrying out interventions within the subsoil to reduce the inclination and prevent the tower from toppling over, according to ABC News. Engineers eventually stabilized the structure in 1996.

Leaning Tower of Niles, Ill.

If the citizens of Niles, Ill. can't get toPisa to see the famous 800-year-old leaning tower, there's always their own tilted wonder -- a half-size replica of Italy's famous attraction, perfectly executed, down to the lean. Completed in 1934, exactly 600 years after the Leaning Tower in Pisa (a sister city of Niles, Ill.) was completed, Niles' Leaning Towerwas a utility tower, made from steel, concrete and precast stone, designed to store water, according to ABC Chicago. A plaque at its base says it was built to honor the outstanding scientist Galileo Gallilei. And while this leaning tower's tilt is unintentional, like the original tower, it underwent recent restoration work. In 1995, a $1.2 million renovation of the Leaning Tower of Niles was started in 1995 and was completed in 1996, improving the structure, facade and the Plaza area, according to the Niles Herald-Spectator. The Leaning Tower Plaza area today has four fountains and a 30-foot pool, and is host to a summertime concert series.

Leaning Tower of Kilmacduagh, Ireland

Located about three miles from the town of Gort in County Galway, Ireland, the Kilmacduagh Monastery, founded by St. Colman, is home to a round tower known for its noticeable lean of approximately 2 feet. The structure dates back to the 10th century and served as a belfry, watch tower, treasury and places of refuge from marauders, according to All-Ireland.com. The round tower, topped off by a conical cap, is one of the tallest in existence, measuring about 90 feet tall, with the only doorway some 22 feet above ground level. Like many leaning structures, the tower of Kilmacduagh was built on soft soil, which may explain its tilt. The tower once had a bell which was said to have been thrown into a nearby lake, according to RoundTowers.org. Legend has it that backaches can be cured by laying on St. Colman's grave that lies behind the cathedral in the complex.

Towers of the Asinelli and Garisenda, Italy

The most prominent of the Towers of Bologna in Italy, the Towers of Asinelli and Garisenda have defied gravity since they were built by patricians in the 12th century. The smaller tower is theGarisenda, which measures about 162-ft tall andtilts about 11 feet from perpendicular as it wasn't built on a solid foundation,according to Frommers.In 1360, part of the tower was cut off for safety reasons, and access to the Garisenda is still not allowed.

The taller of the towers, the Asinelli, measures about 334-ft tall and inclines about 7.5 feet. Visitors can climb the 498 steps to the top of the Asinelli for stunning views of the Bologna Cathedral (Cattedrale of San Pietro), the Basilica of San Petronio, the ancient medieval streets criss-crossing the city, and the Bologna hills, according to ItalyGuides.it. Scientists have reportedly used the tower to conduct experiments about the earth's rotation, and during WWII, it was used as a watch tower, where volunteers were positioned during bomb strikes to help dispatch ambulances.

Leaning Temple of Huma, India

The world's only leaning temple, this tilting structure is located in the village of Huma, in the Indian state of Orissa and is dedicated to the Hindu god Shiva. The shrine is built over a rectangular platform with a length of 200 feet and a width of 120 feet, according to the Odisha Review. The main temple leans toward the northeast side (the river side), but while popular belief dictates that the strange inclination has remained constant for 50 years, the purpose of the shrine's tilted position remains shrouded in mystery. Some scholars believe that the temple was designed to lean in purpose, to protect it from violent currents of two nearby rivers during monsoon floods. This theory would explain why the inclination has remained unchanged, unlike with other unintentional leaning structures, such as Pisa. Others, however, believe that the temple gradually tilted over the years due to the depression of the foundation toward the riverside, caused by flood waters, says theOdisha Review.

Leaning Tower of Zaragoza, Spain

The Leaning Tower of Zaragoza was the first large building completed in the Spanish city during the16th century. It was built to house the public clock and its bells, installed in 1508, regulated the life of the city. It was leaning around 9 feet from the vertical since shortly after its construction, possibly due to the short time that was used to make the base and the first body: the south side of the tower hatched faster than the north, resulting in a difference in tensions of both sides that inclined the tower. Many in Zaragoza did not like the tilting tower due to safety concerns. Thus in 1892, officials decided to demolish the structure, a decision opposed by many intellectuals and citizens, who called the "towercide" one of the biggest artistic crimes in Spain. Demolition of the tower was completed in 1893, and today, a mark on the pavement of the tower's perimeter and a sculpture of a seated boy looking at where the structure once stood serve as memorials to Zaragoza'sonce-majestic Leaning Tower.

Capital Gate, Abu Dhabi, UAE

The Capital Gate, the world's furthest leaning man-made tower, in Abu Dhabi, UAE. (Courtesy of ADNEC)

In 2010, Capital Gate in Abu Dhabi, built to lean 18 degrees westward, was named by the Guinness Book of World Records as the world's furthest leaning tower. The 525-ft tall, 35-story skyscraperwas able to achieve its inclination through an engineering program that allows floor plates to be stacked vertically from the 12thfloor up, according to the Daily Mail.The tower'sdiagridwas especially designed to absorb and channel the forces created by wind and seismic pressure, as well as the gradient of Capital Gate. According to Abu Dhabi National Exhibitions Company (ADNEC), Capital Gate also features "the world's first known use of a 'pre-cambered' core, which contains more than 15,000 cubic meters of concrete reinforced with 10,000 tons of steel."

(For More Travel, Follow us on Facebook)