After a few hours of trekking through the darkness, we crested a pile of rocks and were greeted with brilliant sunlight. It poured through a wide gap in the roof of Son Doong, the world’s largest known cave, illuminating a carpet of vibrant green plants growing on limestone rock formations. We were among the first visitors ever to witness this magnificent scene. In 2010, British explorers Deb and Howard Limbert finished mapping the 3- to 5-million-year-old cave—which lies hidden below central Vietnam’s Phong Nha-Ke Bang National Park—after a local man named Khanh Ho discovered the entrance while out hunting two decades prior. Oxalis Adventure Tours (six nights from $3,000 per person) now operates 10-person expeditions developed by the Limberts themselves, and accompanied by guides, chefs, and porters. They take travelers through Son Doong’s cathedral-like chambers, filled with dense jungles, river rapids, and even white-sand beaches.
In the early morning, the River that flows through Phong Nha village stands calm. Later in the day the water is crowded with boats ferrying passengers against the current to the area’s most accessible and popular attraction, Paradise Cave.
Visitors to Son Doong cave must overnight in the gigantic Hang En: itself large enough to accommodate a jumbo jet. The river that flows through this cave ultimately carves its way through Son Doong. On the beach below, porters have erected tents for the night while chefs prepare food for the evening’s feast.
A phenomenal sunbeam show in the first of the two almighty roof collapses inside Son Doong. This sunbeam tracked across the cave floor unbroken for a full hour, casting a hushed wonderment over our group.
After night fell I climbed back up from the campsite inside the cave to reach the jungle flourishing in the space beneath the collapsed roof. Not normally one for selfies, I couldn’t resist using a long exposure with a shutter remote to capture this shot.
From the road where trekkers are dropped off at the start of the adventure a descent follows a steep path down to the valley floor through overgrown jungle. A the foot of the path, the group stops to refill water and refresh in a cool stream. Here, one of the porters takes a well-earned smoke break.
On the trek into and out of Son Doong, trekkers pass through Ban Doong village. This is home to a small community of Bru Van Kieu minority people. The village school comprises one room for all the kids and a small space at the rear for the teacher to sleep in during term time.
Hang En Cave, the prelude to Son Doong, is in fact one of the highlights of the experience for many. The trek to Son Doong cave involves an overnight stay in this gigantic cavern: itself large enough to accommodate a jumbo jet. The river that flows through this cave ultimately carves its way through Son Doong. On the beach below porters have erected tents for the night while chefs prepare food for the evening’s feast.