Cave men

Light from one cave explorer's torch reveals the colorful stalagmites within Tangren Cave in Fangshan district. Photo: Courtesy of Beijing Caving Association

Beijing Caving Association members delve into Tangren Cave in Fangshan district, which is filled with interesting mineral deposits.Photos: Courtesy of Beijing Caving Association

Beijing's mountainous suburbs have made this city an ideal place for outdoor sports, but along with great heights, there are great depths to be explored as well. Under the surface, Beijing holds karst caverns of stunning beauty and thrilling adventure.

Cui Qingwu, a 26-year-old guide for Beijing Haicheng Outdoor, has been spending his spare time caving for the past three years. Now he's also the director of the 20-member Beijing Caving Association, a semi-professional organization which aims to explore and record the natural caves around Beijing. Cui told Metropolitan that caving has quickly become his favorite outdoor activity, ahead of his other passions, rock climbing and hiking.

"Hiking and climbing are my job. When I found I had finished most of the surrounding mountains of Beijing, I felt bored and realized I can no longer be entertained by hiking or climbing," Cui said.

Cui first stumbled upon caving while on a hike in Fangshan district. He found a cavern that looked unexplored.

"I decided to give it a try with my climbing skills to find out what's inside and to explore how deep it is, and was quickly hooked by that experience," said Cui.

Since then, he's explored caves as deep as 398 meters. That cave even had its own underground river.

The darkness of caves amazed Cui, and helped him regain the feeling of adventure he'd lost with hiking and climbing.

"When you are going down on a rope, the only light source is your headlamp. You can only see what's inside its range and have to prepare for everything under your feet. Maybe it's a steady rock platform, but more likely it's a slippery stone," Cui said. "This kind of uncertainty is the spirit of exploring, and I just love it."

Underworld to wonderland

Gao Jia, 34, another member of the caving association, told Metropolitan that he's more attracted to the scenery inside caves than the adventure involved in getting there.

"Most people would naturally think the underground world is too dark to see anything," said Gao, an office administrator at a car manufacturing company. "That's partly right, as when you're working on a rope, you can only carry a headlamp. But when we reach the bottom, we can bring out lights that provide strong light, and everything can be illuminated thoroughly."

What he sees in the light are colors - whites, yellows, oranges - reflecting off of the hanging stalactites (mineral deposits on the ceiling) and crystals.

"Inside the range of light you see a gaily-colored mosaic, and outside the light it's complete darkness. The sharp contrast turns the underworld into a wonderland," said Gao.

While the artificial light plays with the rocks in interesting ways, it also plays interesting tricks on the mind. Cui said it's hard to understand the passage of time without natural daylight.

"We have to check our [headlamp] batteries regularly in order to remind ourselves not to stay too long underground," Cui said.

The pleasant environment, with clean air and a year-round average temperature of 15 C, also keeps many spelunkers underground for extended periods.