Tourist caves in the United States lean toward the disappointing—paved trails, teenage guides spouting corny dialogue, stalactites bathed in the purple stench of theater stage lights. That's why I was excited to find out about Venado Caverns, a cave in north central Costa Rica. My guidebook advised me to think long and hard about any issues I might have with either claustrophobia or bats before going on a tour. Clearly, that meant it would be awesome.
And it was. When you get to Venado Caverns, you're given a pair of rubber boots and a helmet with a light on it, and sent out tromping across a muddy pasture to a spot where a little creek flows out of a gaping, ragged cleft in the side of a hill. This is, as they say, more like it.
But the freewheeling sort of tourism at Venado has its own drawbacks. What you gain in wild, unfettered adventure, you lose in cave preservation and public understanding of what's actually going on in the world beneath.
To that effect, it's somewhat telling that the real name of the cave is lost in tourist rhetoric. Venado is a town near the cave. Gabinarraca is the actual name, a fact I heard nothing about until I talked to Gustavo Quesada, president of Costa Rica's national caving society, Anthros. Founded in 1995, Anthros is the largest caving group in Central America and is in charge of the national caves registry for all of Central America, through its project ICEKE (Central American Institute for Karst and Speleological Studies).
Quesada was able to shed some light on things I noticed in the cave that my tour guide couldn't really explain, and he corrected some "facts" the guide led me astray on.
First, a little background. Gabinarraca is the second longest cave in Costa Rica, at just over 8,900 feet long. But it's not a deep cave, in the sense of elevation. In fact, from the main entrance, Gabinarraca actually rises about 114 feet. It's really a mostly horizontal tunnel through the hillside, with lots of water passages, which is part of what makes it such a great tourist cave—there's no serious rock-climbing or rappelling skills required.
What is required is a certain level of comfort with tight spaces. Several times, I had to scuttle through a tunnel on my hands and knees. Once, even that was too tall, and I ended up army crawling on my belly. I waded and forded running water from the creek, and splashed around an underground waterfall. At one point, the guide had us shut off our helmet lights and we stood in thick blackness so dense I couldn't see my hand even when it was touching my nose. In short, it was an amazing experience, but the sort of amazing experience that could give some people panic attacks.
Another thing about my tour of Gabinarraca that was very different from any cave tour I'd been on in the United States: How often we were encouraged to touch things. In particular, a large formation called 'The Papaya', which our guide told us to lean against or hug for a photo op. I thought you weren't supposed to touch cave formations, but the guide told me The Papaya was, essentially, a dead formation, so I couldn't harm it.
That's not true, according to Quesada. The Papaya is a flowstone, formed from layer upon layer of calcite left behind on a rock by a thin, continuously flowing film of water, he said. And it's still growing. Touching it can chip off layers of calcite, or leave behind skin oils and mud that alter the flow of water and change the formation.
When I touched The Papaya's wet, rough, snakeskin-like surface for this picture, I probably damaged it.
My guide also misidentified Gabinarraca's other major formation—The Altar. The chalk white steps of The Altar look like a brain, and the guide told me it was 3 million-year-old petrified brain coral.
Wrong again. Instead, The Altar is a series of rimstone dams, Quesada said. They form when pools of calcite-saturated water basically dam themselves up by depositing a wall of calcite along their overflow edge.
"In this case, the rimstone dams are very small. But in other places, like Belize, there are caves where the dams are so big that you can swim in them," Quesada said.
In the U.S., programs like Geoscientists-in-the-Parks get experts involved in what the public hears about caves. Even when the actual tours are led by non-experts, the facts often come from summaries written by scientists. There's no analogous program in Costa Rica.
I'm glad I got the opportunity to visit a "wild" cave like Gabinarraca, but it's been disheartening to see how little factual information on the cave makes it to tourists—even on the Internert, there's little outside of Anthros' site. Ultimately, I'm not sure the adventure experience is worth the trade-off in preservation and information.
All photos in this post are the work of a photographer from Video Producciones Arenal, who accompanies tour groups into the cave with a waterproof camera kit.
Maggie Koerth-Baker is the science editor at BoingBoing.net. She writes a monthly column for The New York Times Magazine and is the author of Before the Lights Go Out, a book about electricity, infrastructure, and the future of energy. You can find Maggie on Twitter and Facebook.