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