When we last heard from photographer Ryan Deboodt, he’d just piloted a drone camera through the earth’s largest cave, Vietnam’s Hang Son Doong. Now he’s back with a short film that’s every bit as striking: a kayaking trip on the Xe Bang Fai River in the Tham Khoun Xe cave in Hin Nam No National Protected Area in central Laos.

The cave is more than four miles long and averages about 250 feet wide and 120 feet tall. Locals have fished near its entrance for centuries and climbed the walls to gather eggs from bird’s nests. Paddling it isn’t new, either-the first Europeans came in 1904 and the first raft journey came just a year later. Tham Khoun Xe was then closed to outsiders for nearly a century, until opening to kayaking 10 years ago.

See more of Deboodt’s photography at his website, Vimeo, Instagram, and Facebook.

Steve Casimiro is the editor of Adventure Journal. Follow him on Instagram at @stevecasimiro.