This route connects three distinctive landscapes within Phong Nha – Kẻ Bàng National Park: primary forest, large limestone caves, and a hidden valley pool surrounded by karst mountains. After trekking through the forest, the terrain opens into Ma Da Valley, where a clear turquoise lake forms from streams emerging from the limestone mountains. The path then leads into Hang Voi, a massive dry cave with high ceilings and a cavern space that feels like a natural underground hall. The route later connects to Hang Trạ Ang, where water flows through the mountain and creates a long cave-swimming section. Passing through forest, valley water, and underground caves in a single route reveals the diversity of landscapes within the core zone of Phong Nha.