Cruise in a long-tail boat through a natural tunnel of total darkness as the Nam Hinboun River drills 7,5 kilometers through a mountain at Kong Lor Cave. The river runs about 30 metres wide with a limestone ceiling up to 100 metres high, and it flows by sandy beaches and rock formations named for their shapes: “Buddha”, “frog”, “owl”, “soft-shell turtle”, and “fish trap”. According to local lore, five Kong Lor villagers first navigated the tunnel to Ban Natan in the 17th century. Today, the villages offer boat excursions through the cave, overnight lodge stays, and trekking options inside protected areas, including a hike to the 70 meters-high Nam Sanam Waterfall.