Of the many dusty sawngthaew rides I've been on in Laos, this one was the dustiest. The grasses and shrubs on the side of the road are all coated in a fine layer of dirt, looking as if they've been bronzed, and by the end of the hour and a half trip from Ban Na Hin to Ban Kong Lo there's dust in my ears and tiny beaches have formed in the folds of my clothes.
Tham Kong Lo, the seven kilometer long cave where the Nam Hin Bun flows through a mountain in Khammuan Province, can be visited as a day trip from Na Hin, or you can stay overnight in one of several guesthouses in the villages between Na Hina and Kong Lo. Alternatively, you can opt for a homestay -- 50,000 kip including dinner and breakfast -- in Kong Lo Village. To arrange a homestay simply show up and look confused.
Another kilometer's walk down the road the sawngthaew came in on I arrive at the banks of the Hin Bun River. I pay the local boatmen's union 100,000 kip to hire a boat and another 5,000 for the cave entrance fee. After ferrying to the other side of the river I get out and walk a path into the cave while the two boatmen ford the vessel over the rocks near the cave's mouth.
The boats are long narrow wooden skiffs that can seat one to three passengers. The boatman aft operates the motor-rudder combo, while the boatman fore scans the river ahead, watching for rocks and shallows and occasionally using an oar like a punter's pole for propulsion or separation. He rarely needs to give the pilot directions. Both men wear large battery-operated headlamps that provide the only light inside the pitch black cave. I have a simple LED model that's fine for reading in bed but is next to useless for illuminating the more distant corners of the tunnel. That said, it does help somewhat and is essential to see where I am stepping when I periodically need to get off the boat in shallows or small rapids. Don't take the trip without some kind of flashlight. Also necessary are rubber-soled sandals, and you may want to wear a light jacket, as the cave is rather chilly.
As we move into the cave and the bright daylight streaming into its interior diminishes and then disappears completely, a genuine feeling of exploration creeps in. The cave is huge,100 meters wide and almost as high in some places, and mostly unseen, everything that doesn't fall inside our beams of light is mystery. The experience feels unique and susceptible to chance and discovery. Even when a returning boat with its own paying customers passes going in the other direction, I can see nothing more than their own circles of light, like the glowing orbs of deep sea creatures.
About halfway through the tunnel we stop and the pilot takes me ashore. We scramble up the slick bank to view a grouping of stalactites and stalagmites. Many of them are small and pointed, like the teeth of some great predatory fish. The pilot doesn't speak any English and, rightly assuming, doesn't even bother trying to speak Lao to me. But he's an erudite grunter and I have no trouble discerning his meanings: Watch your step. Come this way. Get a load of this one.
When we arrive at the other end the light and warmth that come with it are more than welcome. As we exit another boat is entering, this one filled with three locals and produce, a reminder that the river still serves a more elemental purpose.