Tu Lan Cave System

A ladder 15 meters long drops into Hùng Tôn Cave. Below it there is only darkness. The headlamp of the person ahead lights up the rock wall, and a safety rope holds whoever is climbing. Rung by rung, the group goes deeper into the mountain. This cave holds something strange. There are traces of fossil sea creatures, here among the mountains and the forest.

Sea creatures, inside limestone mountains? That question can wait for the foot of the ladder. For now, go back to the morning, when the road is just beginning.

From Phong Nha, the car drives about 70 kilometers northwest, along the Hồ Chí Minh Road. It stops at the village of Tân Hóa, about 112 kilometers from Đồng Hới. On the old map, this area was Tân Hóa commune, in Minh Hóa district. That district was part of Quảng Bình province. Since the provinces were reorganized, the area has belonged to Quảng Trị province.

Tân Hóa is a small rural village that has suffered many severe floods. Even so, in 2023 the United Nations World Tourism Organization named Tân Hóa one of the Best Tourism Villages in the world. The village was chosen for the rich culture and nature of the area, and for its commitment to sustainable tourism. Its people have turned to welcoming guests as a lasting way out of poverty.

Closely tied to the village is Tú Làn. It is not one cave but a whole world inside the limestone mountains. There are more than 20 caves, eight valleys and rivers that run underground. Together they spread across more than 650 hectares. The system stands on its own, outside Phong Nha Kẻ Bàng National Park.

The people of Tân Hóa have known some of these caves for a very long time. In 1992, a British and Vietnamese caving expedition came to survey the system for the first time. Then in 2009, a local man named Đinh Hồng Nhâm was walking in the forest and fishing near the cave mouths. He found two more caves, Tú Làn Cave and Tố Mộ Cave. From 2010, the explorers came back for deeper surveys. And the caves kept appearing, one after another. In 2015, a cave named Tiên 2 was found. It is more than 2.5 kilometers long.

No one may enter these caves on their own. Only one company is authorized to take visitors into the Tú Làn system, and every group walks with a guide.

The day route is rated easy, yet it is far from short. It means 9 kilometers of walking on forest trails and 800 meters inside caves. There is a ladder of 15 meters, and a swim of about 150 meters through an underground river. Families with young children take a lighter route, with 6 kilometers on foot and 300 meters inside caves. For those who want to go farther, there are trips of three to five days. They camp in the jungle and cross deeper valleys.

That morning, after everyone receives their gear, the group sets off on foot. The path leads past the corn fields and peanut fields of Tân Hóa, then across the Rào Nan River. On both sides lie limestone valleys and primary forest. No one sitting in a car would ever see this.

The first cave is Hang Chuột, the Rat Cave. It is a dry cave. Its vaulted ceiling is high, stalactites hang down, and its entrance is shaped like a heart. At Tú Làn, the caves lie in layers. The caves higher up are usually dry, full of stalactites and calcite formations that are easy to see. The caves lower down are water caves, with underground rivers, small waterfalls, or pools of water at their mouths. In one day, a walker meets both kinds and sees why they belong to one system. The Rat Cave is a good place to ask each other how a dry cave differs from a water cave, because a water cave comes right after.

Leaving the Rat Cave, the group climbs the slope that people call Baby Hill. It crosses the Hùng Tôn valley and reaches the mouth of Hùng Tôn Cave. This is the ladder of 15 meters from the beginning. At the foot of the ladder, the question finds its answer. The fossil sea creatures in Hùng Tôn Cave show that the limestone here began as sediment on the floor of an ancient sea. Later, that rock was lifted up. Then, over millions of years, water slowly wore it away and carved out caves.

Next comes the underground river. Life jackets on. Headlamps switched on. Each person stays close behind the next, swimming about 150 meters through the dark water. Ahead, the far mouth of the cave appears, opening onto the Tố Mộ valley.

Out of the darkness, the group steps into the light, in the middle of a green valley. It is a moment that is hard to forget.

At Tố Mộ, the group stops for lunch. Anyone who wants to can swim in a blue lake or a stream. Afterward, everyone walks back to the village of Tân Hóa and washes up. In the evening, the car takes them back to Phong Nha.

If one day you climb down that ladder in Hùng Tôn Cave, remember that you are going into an old seabed that became a mountain, and then a cave. And when you swim out of the darkness at the far mouth, the sunlight of the Tố Mộ valley will meet you. Around it are limestone mountains, underground rivers and primary forest, still wild.