Hang En

Flocks of swallows nest inside Hang Én, the Swallow Cave, and the cave takes its name from them. That is a fact of the cave's ecology, not a legend.

If Sơn Đoòng is the mountain peak, Hang Én is the road that leads up to it. The six-day journey to Sơn Đoòng begins with a night camped inside Hang Én. But Hang Én is not only a stopover. It is one of the largest and most beautiful caves in the Phong Nha area, and it deserves a story of its own.

The cave lies in the core zone of Phong Nha Kẻ Bàng National Park, in Phong Nha commune, Quảng Trị province. Sơn Đoòng is about three kilometers away along the river valley. The Rào Thương stream made the cave, as its water slowly wore away the limestone.

According to figures from Vietnam's national tourism authority, Hang Én is more than 1,645 meters long. It is 120 meters high and 170 meters wide, and it has three entrances. Oxalis Adventure, a tour company, measured the cave more precisely. The two sets of figures differ a little.

Oxalis puts the volume at up to 6.7 million cubic meters. The ceiling reaches 145 meters at its highest, and the widest chamber measures 200 meters.

Oxalis also records that the Arem people have known this cave for a long time. They once climbed the high rock walls inside to catch birds, for their meat and for their nests. It was a way of making a living that tied people to the cave for centuries before visitors appeared.

In 1994, an expedition of British and Vietnamese cave explorers carried out the first survey and mapping of Hang Én. That work helped the cave become much more widely known.

Inside, a campsite lies on a sandy bank about 700 meters from the entrance. The ceiling above the camp can rise as high as 140 meters. Beside the sand are a turquoise lake and an underground river. A night here, under a vast vault of stone, comes with the sound of water and the sound of the swallows.

In the dry season, from December to about February, sunlight shines deep in through the entrance and makes a strange patch of light in the darkness. That light explains why Hang Én is a destination for many photographers. In the rainy season, floodwater can rise inside the cave within just a few hours.

People lived alongside Hang Én long before anyone spoke of tourism. The Arem climbed the rock walls for nests. The Bru-Vân Kiều live in Bản Đoòng, a village on the way into the cave. And the water of the Rào Thương still flows through, still wearing away a little more rock each year, still writing a story of the earth longer than any story people could tell about this place.