Ancient cave discovered 180 metres underground in China

(Patria) - A huge ancient forest world has been discovered 180 metres underground, in a large sinkhole in China, writes the Daily Mail.

The underground mystery in China's "Geopark" was stumbled upon by a team of cave exploration scientists in May last year.

The phenomenon is also known in China as "tiankeng" or "heavenly pits".

The UNESCO Global Geopark Leye Fengshan, where the sinkhole was found, is located in the Guangxi Zhuang Autonomous Region, in southwest China.

The geopark is described on the UNESCO website as "primarily sedimentary with more than 60% of 3,000-metre-thick Devonian to Permian carbonate rocks."

It is known for being "an area of caves and the longest natural bridge in the world," reports Jutarnji list.

Researchers said the primitive forest could be home to previously unidentified plant and animal species, reports The Washington Post.

Giant sinkholes are not uncommon for such areas in China.

The Chinese government's state news agency Xinhua published an official report stating that the new discovery has brought the number of sinkholes in the country to 30.

Zhang Yuanhai, a senior engineer at the Chinese Geological Institute, also told Xinhua that the site has a 'well-preserved primitive forest at the bottom' and three caves in the walls.

They added that the sinkhole is 306 metres long, 150 metres wide and 192 metres deep, with a volume exceeding 5 million cubic metres, meaning it can officially be categorised as a large sinkhole.

Chen Lixin, leader of the Guangxi 702 cave expedition team, said the dense shade of plants reaches shoulder height and added that the ancient trees growing at the bottom are nearly 40 metres tall.

The cave expedition was completed by a team that descended by rope more than 100 metres and "hiked for several hours to reach the bottom of the pit."

The landscape in the Geopark is a karst area, meaning it consists of limestone. Sinkholes usually form by the dissolution of bedrock by groundwater and are common in that area.

However, the unique forest found at the bottom is unusual - it looks like something out of a fantasy film.

The forest was able to grow thanks to the shape of the hole, allowing enough light to enter while also being deep.