Backpackers set up tents on a plank road on a cliff in Laojun Mountain in Luoyang, Henan province, July 16, 2016.[Photo/IC]

More than 100 backpackers slept in their tents while perched on a 1,700-meter cliff face after they set up tents from Friday to Saturday along a plank road that hugs Laojun Mountain in Henan province.

The spine-tingling campsite, however, rewarded them with breathtaking views of the sea of clouds that fills up the valley below like an expanse of water.

Xu Lei, one of the backpackers and an organizer of the trip, said that for the first time, they moved campers from the bottom to partway up the mountain to get a better view of the sea of clouds and the sunrise.

"We started to climb on Friday evening and made camp at the hanging plank road, about 1,700 meters high," Xu said. "That area is on the back of the mountain with little wind and does not open to ordinary tourists. It is a relatively comfortable place for backpackers."

The walkway also has a railing that kept the campers from rolling off in their sleep.

"The view of the sea of clouds started at 10 pm on Friday and continued til 5 pm on Saturday," Xu said. "It gave me an extraordinary experience. It looked like I was in the middle of the ocean. The cloud-shrouded mountain looked like a sailing boat."

The camping trip was part of a series of activities for Laojun Mountain Camp Festival, which started on Saturday. The organizer provided water, portable toilets and flashlights. Many campers got up early to exercise in the presence of the cloud sea on Saturday morning.

Laojun Mountain, at 2,200 meters, is the holiest site for Taoist priests, since the founder of Taoism, Li Er, secluded himself on the mountain on the eighth day of a fourth lunar month in the fifth or sixth century BC. The high altitude, thick forest and humid conditions make the mountain a perfect place to view the phenomenon of the sea of clouds.

Qu Wei, 28, a tour guide at Laojunshan scenic spot, said besides cliff camping, many tourists enjoy doing yoga, playing the seven-string Chinese zither and taking videos with the background of the sea of clouds. "It was very thrilling to do yoga at an altitude of 2,000 meters," she said. "The scenic spot is covered with Wi-Fi, which enables tourists to share their experience on social networking sites or apps."