Konglor Cave is one of the great natural wonders of Southeast Asia, a limestone tunnel about seven kilometres long through which the Nam Hin Bun river flows from one side of a mountain to the other. Visitors travel through it by long wooden boats, powered by small outboard motors and steered by local guides, sitting in near darkness with only headlamps to light the way. The cavern is vast, with ceilings that disappear into blackness, and in places formations of stalactites are lit up in colour. Midway, you stop and walk through a chamber filled with towering shapes of rock.
The road to the cave leaves the main highway and runs for about forty kilometres through farmland and forest, with the limestone peaks rising on both sides. The surface is mostly sealed, though it narrows and has potholes, especially in the wet season, and village life spills out on to the road with children, chickens and buffalo. Corners are gentle, with the occasional sharp bend, and the views of cliffs at the end of fields are fantastic. In the dry season the dust can be thick behind trucks.
The valley around the cave is home to villages of Lao and minority peoples, who farm rice and tobacco and fish in the river. A handful of guesthouses and homestays near the cave offer food and a bed, and boat tickets are bought at the entrance. The river through the cave can run high after heavy rain, and boats do not operate in floods, so allow flexibility.
Fuel is not available near the cave, so fill up in Ban Na Hin before coming here, and carry spare if your bike has a small tank. Bring a torch or headlamp, a waterproof bag for your phone and a change of dry clothes if you plan to walk. The cooler months, from November to February, are the best time to visit. Sunsets over the fields are magnificent.