Image copyright Barcroft Image caption Surrounded by forest the experience is au naturel in more ways than one

China's recent obsession with glass tourist attractions has gone round the U-bend with the opening of some see-through treetop public toilets.

The loos, near Shiyan Lake in southern Hunan province, have fabulous views of both the forest below and other people using the facilities.

Cubicle walls, even those between the men's and women's sections, are only separated by lightly frosted glass.

But state media said few visitors dared use the loos on their opening day.

Image copyright Barcroft Images Image caption Shy users of the urinals may take comfort from the privacy barriers between them, though not in the fact they are made of glass

Despite a boom in the construction of glass bridges and walkways in scenic locations in China in recent years - in some cases so popular they had to be closed - these are thought to be the first entirely glass public bathrooms in the country.

However, it not the first time those busting to go have been exposed a little more than they might like by the enthusiasm for glass.

There were reports recently of some male toilets in a university dorm in Hunan which included one very public cubicle.

Image copyright Barcroft Image caption Unusually, a head for heights is a requirement for a job as a cleaner there

Image copyright Barcroft Image caption Awkward: cubicle walls are only lightly-frosted, even between the men's and women's sections

News of the wide-view WCs at Shiyan Lake sparked a range of reactions online.

Responding to a Facebook post about it by state television channel CCTV, Ejike Nnadi summed up the feelings of many: "Hell no."

Others were more taken by the idea. "You'll be surprised by what you can tolerate when you really, really need to go," said one post.

Another nodded towards another modern use for restrooms: "I'd be in there 'til my battery hit zero if there was signal in there!"

Image copyright Barcroft Image caption The well-lit lavs are built on a steep hillside

Tina Chen took a dimmer view of all such projects though. "(It) is not about being shy, just again someone had extra money to waste."

Image copyright Getty Images Image caption Unusual glass structures have provided popular photo ops for tourists across China

Awkward or not, it is hoped that these bathrooms for the brave will encourage tourists to visit the countryside around Changsha city and admire the spectacular autumn colours of its forests.