1. In more than 30 years as a cave explorer, photographer and guide, John Spies – an Australian based in Thailand – has visited 85 caves, discovered incredible formations.
2. John has discovered caves never before visited by humans and his expertise in the field has led him to work with Sir David Attenborough on his acclaimed Planet Earth BBC television series.
3. John runs the Cave Lodge guest house in northern Thailand where prices start from just £2 per night and adventure tours to the caves.
4. A caver gazes at a stone formation in Tham Lum Khao Ngu (Snake Mountain Cave) in Kanchanaburi, Thailand, which houses the world’s tallest cave.
5. Ian Robinson explores the Tham Pha Puak (White Cliff) Cave in Pang Mapha, Thailand
6. Dave Pierce examines an enormous flowstone in Tham Pha Mon cave in Pang Mapha, Thailand
7. Shan Man Ong, standing on a bamboo raft, explores the downstream entrance of Tham Lod cave in Pang Mapha, Thailand
8. John Spies explores the Tham Lod in Pang Mapha, Thailand
9. Dave Pierce stands on a ledge at the entrance to the Tham Nam Lang cave in Pang Mapha, Thailand
10. Kerry Hamilton climbs a cave rope attached to bamboo scaffolding to scale a waterfall inside Tham Susa cave in Pang Mapha, Thailand