9 tourist attractions that are dying

By Milena Veselinovic, for CNN

Updated 1158 GMT (1958 HKT) July 28, 2015

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"Tourism is not regulated well enough and the massive influx is putting a strain on sites all over the world," says Stefaan Poortman, executive director of the Global Heritage Fund. "The most well-known sites like Angkor or Machu Picchu are really swamped with tourism."

Photos: Dying tourist attractions

Machu Picchu – "Tourism is not regulated well enough and the massive influx is putting a strain on sites all over the world," says Stefaan Poortman, executive director of the Global Heritage Fund. "The most well-known sites like Angkor or Machu Picchu are really swamped with tourism."

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It was originally built to defend an empire, but now parts of the Great Wall of China are crumbling so badly they need someone to leap to their defense. About 2,000 kilometers, or 30%, of the ancient fortification built in the Ming Dynasty era has disappeared due to natural erosion and human damage, according to the Beijing Times.

Photos: Dying tourist attractions

Great Wall of China – It was originally built to defend an empire, but now parts of the Great Wall of China are crumbling so badly they need someone to leap to their defense. About 2,000 kilometers, or 30%, of the ancient fortification built in the Ming Dynasty era has disappeared due to natural erosion and human damage, according to the Beijing Times.

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The world's largest coral reef ecosystem hosts scores of marine species, but scientists say that it could become extinct as soon as 2050 due to climate change.

Photos: Dying tourist attractions

Great Barrier Reef – The world's largest coral reef ecosystem hosts scores of marine species, but scientists say that it could become extinct as soon as 2050 due to climate change.

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Cambodia's Angkor Wat was visited by more than two million people in 2013. One of the biggest issues facing the Angkor Archaeological Park is that a few major sites -- namely Angkor Wat, Angkor Thom and the Bayon -- endure the bulk of tourist traffic.

Photos: Dying tourist attractions

Angkor Wat – Cambodia's Angkor Wat was visited by more than two million people in 2013. One of the biggest issues facing the Angkor Archaeological Park is that a few major sites -- namely Angkor Wat, Angkor Thom and the Bayon -- endure the bulk of tourist traffic.

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The ceiling of the Vatican's Sistine Chapel, painted by Michelangelo, attracts millions of tourists each year. Last year a new heating and cooling system was introduced in order to try to combat the harmful side effects of tourism.

Photos: Dying tourist attractions

Sistine Chapel – The ceiling of the Vatican's Sistine Chapel, painted by Michelangelo, attracts millions of tourists each year. Last year a new heating and cooling system was introduced in order to try to combat the harmful side effects of tourism.

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The exquisite 20,000-year-old drawings of bison inside the caves of Altamira, close to Spain's north coast, were closed to the public in 2002 due to fears that the constant trudge of tourists was taking its toll. Last year, access to the caves was partially reopened.

Photos: Dying tourist attractions

Caves of Altamira – The exquisite 20,000-year-old drawings of bison inside the caves of Altamira, close to Spain's north coast, were closed to the public in 2002 due to fears that the constant trudge of tourists was taking its toll. Last year, access to the caves was partially reopened.

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Wildlife roams freely in Kenya's Maasai Mara, drawing in swathes of safari tourists every year. This is putting a lot of pressure on the area's resources, says Stefaan Poortman, executive director of the Global Heritage Fund. <br />

Photos: Dying tourist attractions

Maasai Mara – Wildlife roams freely in Kenya's Maasai Mara, drawing in swathes of safari tourists every year. This is putting a lot of pressure on the area's resources, says Stefaan Poortman, executive director of the Global Heritage Fund.

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Photos: Dying tourist attractions

Tutankhamun's tomb – Moisture from the breaths of decades of visitors has caused the deterioration of Tutankhamun's original tomb, say experts.

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Completed in 1643, the Taj Mahal was built by the Mughal emperor Shah Jahan in memory of his third wife, Mumtaz Mahal, who is buried there alongside Jahan. The site is visited by four million tourists each year.

Photos: Dying tourist attractions

Taj Mahal – Completed in 1643, the Taj Mahal was built by the Mughal emperor Shah Jahan in memory of his third wife, Mumtaz Mahal, who is buried there alongside Jahan. The site is visited by four million tourists each year.