Amazing photographs of huge cave systems in Thailand (18Pics)

ancient caves of Tham Lod in Pang Mapha, Thailand

John Spies stands at the entrance chamber of Tham Susa in Pang Mapha, Thailand, a filming site for BBC's Planet Earth

 Cave in Pang Mapha, Thailand

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 column (62m or 200ft tall)

Ian Robinson explores the Tham Pha Puak (White Cliff) Cave in Pang Mapha, Thailand

Dave Pierce examines an enormous flowstone in Tham Pha Mon cave in Pang Mapha, Thailand

Shan Man Ong, standing on a bamboo raft, explores the downstream entrance of Tham Lod cave in Pang Mapha, Thailand

John Spies explores the Tham Lod in Pang Mapha, Thailand

Dave Pierce stands on a ledge at the entrance to the Tham Nam Lang cave in Pang Mapha, Thailand

Kerry Hamilton climbs a cave rope attached to bamboo scaffolding to scale a waterfall inside Tham Susa cave in Pang Mapha, Thailand

David Pierce checks the Tham Mae Lana flowstone at an underground stream in Pang Mapha, Thailand

John Spies explores the Christmas cave, in Pang Mapha, Thailand

Blue stalactites hang in caves in Pang Mapha, Thailand

White Cliff Cave, in Pang Mapha, Thailand

Suphaporn Singnakphum examines the decorated chamber in Tham Fossil cave in Pang Mapha, Thailand

A pendulite hangs in Tham Pha Mon cave in Pang Mapha, Thailand

A cluster of oolites, commonly known as cave pearls, in a cave in Pang Mapha, Thailand

Vulcanites, a relatively rare formation of floating calcite rafts, are photographed in Tham Pha Mon cave in Pang Mapha, Thailand