Terrified shrieks echoed through the cave's eerie darkness, mingling with the screeches of the bats above us. People squirmed in panic but we were literally between two rocks and a hard place. Passing through A Thread of Sky in Fujian province's Wuyi Mountains means squeezing through a 163-m-long rift that is sometimes less than half a meter wide.
The tightest spots are pitch black at ground level but light shines several meters down through the crevice's opening high above, just enough to trace the silhouettes of bats flitting around. Someone said something about flying rats. My wife said something about vampires. Squashed between those gooey walls, excrement also came to mind.
Finally, we popped out of a slender crack into searing sunlight, which illuminated the limestone spires, looping rivers and fragrant tea gardens that make Wuyi Mountains a splendid travel destination.
Our subterranean experience seemed antithetical to the hours we had spent clamoring toward towering mountaintops. Wuyi's peaks average about 400 m, with its highest - the Three-Layer Peak - soaring 717 m skyward. They are part of a Cathayshan fold system, meaning that millions of years ago, the earth belched out tons of magma, which the sands of time ground into cones and pillars.
The day before, we had scaled the Heavenly Tour Peak to take in the panorama. From 414 m up, the 9.5-km Nine-Bend River looked like a wriggling green ribbon. Fleets of tiny bamboo rafts traced its course as far as the eye could see.
The peak and its views resembled those of the colossal Roaring Tiger Rock, except for a stone Buddha - about 24-m-tall - chiseled into Roaring Tiger's cliff-face in 1992. But this likeness wasn't the only thing carved into the bluffs. Throughout the ages, the splendor of Wuyi's peaks have so deeply inspired poets, they didn't just write about them, they wrote on them.
More than 400 prose inscriptions are etched into the gorges flanking the Nine-Bend River and are collectively known as the Calligraphy Garden. These can be seen from the hundreds of bamboo rafts that drift along the river.
Oarsmen croon folk ballads as they pull these vessels along the waterway by jamming long poles into the stony riverbed. Small caverns pocking the surrounding bluffs warehouse the ancient remains of these boaters' ancestors by blood and predecessors by trade. Several are entombed in wooden "boat coffins" that date back more than 3,800 years.
Nine-Bend River curls through some of Wuyi Mountains' most imposing bens and Jade Goddess Peak is widely acclaimed as the most beautiful among these.
Legend has it, this limestone monolith was created when the fairy Yunu was lured from heaven by Wuyi's magnificent scenery and fell in love with a mortal man named Da Wang. The Emperor of Heaven was so infuriated that he threatened to turn them into stone.
Yunu retorted: "If it means I can stay in the human world with Da Wang, do it."
It is but one of many myths surrounding Wuyi Mountains. Even the area's name comes from the folktale of two brothers - Peng Wu and Peng Yi - who split the mountains to release the water they held back, creating a fertile paradise for local people.
Wuyi's ecology is particularly ideal for tea cultivation and its rock tea is celebrated as among China's best brews. It is processed in 10 steps and served in 18.
On our first day in town, we met Huang Shuihua, whose family has grown and processed rock tea for five generations. Huang invited us to his home to sample some of their handiwork and chat.
We had arrived during the 20-day May harvest and the fragrance of tealeaves around Huang's home was stiff enough to make us squint.
After showing us the equipment and explaining the processing methods, Huang sat us at an ornately carved wooden tea table with his family. Conversation and teas simmered for hours.
They showed how to properly swill the rock tea. It should first be swished around in the mouth and then noisily slurped with an open maw. Everyone sniggered as I struggled to master the technique, usually gurgling rather than gulping. They applauded when I finally got it right.
I had been worried there might be a surprise bill at the end, followed by a dispute about why we'd never agreed to buy anything. Instead, Huang's family gave us free packets of our favorite tea and drove us back to our hotel.
For the rest of the trip, Huang acted as our driver, guide and friend. Again, I felt a little anxious when he dropped us off at the airport.
He'd earlier said he charged 300 yuan ($43.8) a day as a driver. He hadn't driven us around for more than half an hour a day but he'd helped us find our way around and we seemed to have established a genuine bond.
When I asked what we owed him, he shrugged.
"Whatever," he said.
And he meant it.
It seems Wuyi Mountains' majestic natural landscapes are complemented by an even greater resource - warm and honest local people.
That really made the trip worthwhile.