They are 20 of the most exotic and timeless travel destinations of all time (according to Lonely Planet) and they include mystic ancient monuments, breathtaking spectacles of natural beauty and varied and compelling collections of historical artefacts.

But it seems that even these wonders for the ages cannot please all of the people all of the time and the lukewarm reactions they have provoked the world over are available in all their glory on Trip Advisor.

Whether tourists were underwhelmed by the fussy architecture in the Alhambra Palace, the "overblown sandy ditch" that is the Grand Canyon or thought the Mayan pyramids at Tikal were "just a staircase", they are here for all to see...

1. Angkor Temples, Cambodia: "Just ruins really"

Angkor Temples, Cambodia
Reuters
Angkor Temples

2. Great Barrier Reef, Australia: "Deadly"

Great Barrier Reef, Australia
Reuters
Great Barrier Reef

3. Machu Picchu, Peru: "A travesty"

Machu Picchu, Peru
Reuters
Machu Picchu

4. Great Wall, China: "If bricks are your thing"

Great Wall of China, China
Reuters
Great Wall

5. Taj Mahal, India: "Quite a few tiles have fallen off"

Taj Mahal, India
Reuters
Taj Mahal

6. Grand Canyon, US: "Overblown sandy ditch"

Grand Canyon, USA
Reuters
Grand Canyon

7. Colosseum, Italy: "A horrible experience"

Colosseum, Italy
Reuters
Colosseum, Italy

8. Iguazu Falls, Brazil & Argentina: "Queues were enormous"

Iguazu Falls, Brazil & Argentina
Reuters
Iguazu Falls, Brazil & Argentina

9. Alhambra Palace, Spain: "Repetitive geometry"

Alhambra Palace, Spain
Reuters
Alhambra

10. Aya Sofya, Turkey: "Bare, noisy and half full of scaffolding"

Aya Sofya, Turkey
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Haya Sofiya

11. Fès Medina, Morocco: "One man spat on my partner's shoes"

Fès Medina, Morocco
Reuters
Fez Medina

12. Twelve Apostles, Australia: "Weak"

Twelve Apostles, Australia
Reuters
Twelve Apostles

13. Petra, Jordan: "If Disneyland did animal cruelty"

Petra, Jordan
Reuters
Petra, Jordan

14. Tikal, Guatemala: "It's just a staircase"

Tikal, Guatemala
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Tikal

15. British Museum, UK: "Toilet facilities were excellent"

British Museum, England
Reuters
British Museum

16. Sagrada Familia, Spain: "Pile of ugly concrete"

Sagrada Familia, Spain
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Sagrada Familia, Spain

17. Fiordland National Park, New Zealand: "Nothing to compare with Norway"

Fiordland National Park, New Zealand
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Fiordland National Park

18. Santorini, Greece: "Donkey crap and barbed wire"

Santorini, Greece
Reuters
Santorini

19. The Galapagos, Ecuador: "Sand also isn't the best"

Galapagos, Ecuador
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Galapagos

20. Museum of Old and New Art, Australia: "Wall of Sculptured Vaginas"

Museum of Old & New
Reuters
MONA