Mapping An Unexplored Cave

Want to be an explorer? Want to see places nobody has ever seen? You have three options: become an astronaut, become a deep-sea diver or become a caver.

The first isn’t going to happen for a man my age and the second is expensive, so it’s a good thing I live in one of the best regions in the world to do the third. Cantabria in northern Spain has a large amount of karst, a type of stone that often has caves.

One of them is Luna Llena (“Full Moon”), which has yet to be fully mapped. In my fourth caving expedition in Spain I was part of a team that went to look for new passages. I was thrilled. Seeing unexplored parts of the subterranean world was one of the reasons I got into caving. I didn’t think the payoff would come so quickly.

Luna Llena is at the bottom of an abandoned galena mine from the 1920s. The miners were blasting with dynamite one day and opened up a hole into an unknown cave. It’s been regularly explored ever since but there are still many blank spots on its map.

The mineshaft slopes sharply down into the bedrock. Walking along an old narrow-gauge track past ore wagons and rusted equipment, we soon arrived at the cave. There were four of us, two experienced cavers who would be doing the bulk of the mapping, myself, and another relative newbie named Nacho. I quickly discovered that this would be the toughest cave I’d faced in any country.Karst often forms narrow, deep passageways, the product of underground streams cutting away the stone. These passageways can be five, ten, a hundred meters high. There’s no real floor, just a gradual narrowing until you reach water at the bottom. The only way to traverse these is a technique called “chimneying,” in which you straddle the passage with a hand and a foot on each wall. If it gets a bit too wide you press your feet against one wall and your back against the other. You keep tied into a rope running along the wall so you don’t risk falling into the abyss.

This workout led to a payoff – a low chamber filled with soda straws, thin little tubes hanging on the ceiling that eventually form stalactites. We had to crawl on our hands and knees below these beautiful formations for several minutes before getting to a place where we could stand up.

A little more exploring brought us to a long, high passageway. Several small tunnels led away from it, several blanks on the map. We picked one and crawled inside.

This is where it really got interesting. We were off the map in a place nobody had ever seen. Sadly I didn’t have my camera. My Instamatic died the previous week and I wasn’t going to risk my SLR in these conditions. Nacho brought his, but since he was behind me the only shots he got of me were of the bottom of my boots. The tunnel was too small for anything else.

It was almost too small for us to move. Crawling along in a military low crawl, the tops of our helmets scraping against the roof, we came to a spot where the tunnel pinched.

One of the more experienced cavers turned and looked at me.

“You sure you want to do this?” she asked. “Stop and think about it.”

“Of course I want to do it.”

“You’re not claustrophobic?” she asked.

“If I was claustrophobic I would have started freaking out ten meters ago.”

She shrugged and wormed her way into the tunnel. I gave her time to get through and then went in myself. The only way to enter this part was to have both arms stretched out ahead of me. Even then my shoulders barely made it through. I edged my way forward with my forearms and feet, the tunnel pressing in on all sides. Breathing became difficult. There wasn’t enough room to inhale fully, but I was exerting myself and needed the air. Every move was an effort. I wondered if I would make it through. I didn’t panic, though. My only worry was that Nacho was going to have to grab my boots and haul me out.

Any lingering doubt that I have claustrophobia was snuffed out when my headlamp suffered the same fate. An outcropping in the rock hit the power button and the tiny space I was in plunged into darkness.

It didn’t matter. I hadn’t been seeing anything but the rock an inch in front of my nose anyway. Continuing by feel, I made it to a slightly wider part of the tunnel where I could bend my arm and switch on my light. Ahead of me was an even tinier tunnel turning at an acute angle. The caver ahead of me called back.

“Come on through. It’s like a second birth!”

The birth canal I actually had to push off with my legs and force my body through. I exhaled, crushing my chest as flat as it could go. My head and arms emerged in a little cyst in which sat two of our team. Another push and my shoulders made it. A final effort to get the stomach through, swearing all the way to give up beer. I felt the cave walls pressing against my stomach and the small of my back and then I let out a tremendous fart. The cave literally squeezed it out of me.

Poor Nacho. He was right behind me and had nowhere to run. I hoped he didn’t asphyxiate. He was my ride.

We all gathered in the cyst, Nacho looking a bit green around the gills. During all this time our more experienced leaders had been mapping the passageway. Now we got a chance. This was basic mapping, with a compass, tape measure, and clinometer. It was meticulous work in cramped conditions, yet highly rewarding. All my life I’ve studied maps, especially old ones with their tempting blank spots marked Terra Incognita. And now here I was in Subterra Incognita.

I studied every fissure and formation, hoping to find another passage branching away form the one we were in. None were wide enough to push through. The tunnel soon turned back and rejoined one of the main mapped passageways. We’d mapped maybe a couple of hundred meters. In the annals of discovery this is a very minor footnote. I didn’t care. It made all the scrapes and bruises worth it.

So if you want to be an explorer, consider caving. It’s not as hard as you think. I’m 43 years old and only moderately fit. Chances are you can do what I do. If you live in the U.S., the best way to get into it is to join the National Speleological Society. With more than 10,000 members and about 250 local chapters (called “grottoes”), there’s probably a group near you.