Image copyright airbnb.com Image caption The Great Wall stretches for thousands of kilometres across northern China

Airbnb has called off a competition offering the chance to spend a night on the Great Wall of China.

The accommodation site asked people to write a 500-word essay on overcoming cultural boundaries in a bid to win a "once-in-a-lifetime" experience.

But the plan sparked mixed feedback and concerns that it could contribute to the historic structure being damaged.

And according to Chinese media, Airbnb had never received approval from local authorities to run the event.

The firm said it "deeply respected the feedback" and so had "made the decision to not move forward with this event".

'Incredible piece of world history'

The competition offered the exclusive chance to sleep in one of the ruined watch towers on the Unesco-listed Great Wall near Beijing, with a proper bed but neither windows nor roof.

The visit would include a short hike, a "multi-course gourmet dinner" and traditional Chinese entertainment.

Airbnb presented it as a showcase to "promote sustainable tourism to China by spotlighting wide ranging efforts to preserve the Wall's deep heritage".

But when the offer first appeared on the Airbnb website, Chinese social media was quick to pick it up.

Comments ranged from praise for what likely would be a unique night to widespread concerns over being eaten alive by mosquitoes for hours.

Image copyright airbnb.com Image caption The accommodation came with a promise of entertainment and education

There also were serious worries the historic structure might be damaged by the event.

Others said it was wrong for a firm like Airbnb to exploit the landmark for advertising and PR purposes.

According to Chinese state media, the cultural commission in Beijing's Yanqing district which oversees the stretch of the wall where the sleepover was planned, said it was not aware of the event and no approval had been given.

Airbnb said in a statement on Wednesday that "while there was an agreement in place that was the basis for the announcement of this event" it was now being cancelled, apparently because of the feedback.

"One of the goals of our Night At The Great Wall was to highlight how everyone can play a part in honoring and preserving this incredible piece of world history," it said, stressing that the company had worked with experts to help educate people about the wall and preservation efforts.

People who had entered the competition would be contacted about other ways they could "explore and discover amazing experiences in China", it said.

Night at the Great Wall was the latest case of Airbnb offering unique spots via user competitions.

Previous such locations included staying on a reef in the Great Barrier reef, in a research submarine from the Blue Planet II or the castle of historic figure behind the Dracula legend in Romania.