At first glance they don't look real, made in a Hollywood studio perhaps.
But these breathtakingly beautiful photographs are actually from Thailand and they give a glimpse into the staggering other world just beneath the Earth's surface.
Taken by experienced Australian cave explorer John Spies the images highlight the incredible intricacy and colour of strange structures created over millions of years by water slowly dripping through limestone rock.
Some of the scenes captured by the subterranean snapper illustrate the sheer size of the caverns which can contain vast pools of water, high-rise columns and smooth rock domes.
John Spies explores the Tham Lod cave in Pang Mapha, Thailand. It is one of hundreds of caves located in this region and those visiting before sunset can watch the birds entering and the bats exiting in their millions
As the light changes the water and rock formations in the Tham Lod cave take on different hues. There are thousands of fish in the cool underground water
Rays of light flood a large natural entrance to this cave in the northern district of Pang Mapha in Thailand. A small figure peers out from the rocky dim world
Cave explorer David Pierce examines a 21.4metre high column which dwarfs over him at Tham Lod cave in Pang Mapha, Thailand
A majestic view of Tham Lum Khao Ngu (Snake Mountain cave) which houses the world's tallest cave column a monolith that stretches to a staggering 62metres. the downward falling stalactites take on a striking orange colour
The hundreds of stalactites draping from the roof are reminiscent of church organ pipes and when coupled with the huge echoey spaces it is no surprise that the caves have been labelled cathedrals.
The formations are so large that Mr Spies and other explorers face a difficult scramble to achieve their goal of reaching deeper into the cavernous depths.
From the 200-foot world’s highest cave column that is Tham Lum Khao Ngu, known as Snake Mountain cave, in central Thailand to exploring underground rivers draped with impressive rock formations in Pang Mapha to the north of the country these shots show the very best of the nation’s underworld wonders.
In over 30 years as an underground explorer Mr Spies has visited 85 caves in which he has discovered incredible formations, documented prehistoric cave art, ancient underworld burial grounds, Buddhist temples and strange eyeless forms of life.
He says 'I have discovered lots of unexplored caves.
'This includes some of the longest and best decorated in Thailand.
'I have found a new species and genus of cave fish called the angel fish and I have been involved with Thai and foreign archaeologists documenting and recording scores of sites.'
John has discovered caves where no human had visited before and his expertise in the field led him to work with Sir David Attenborough on his acclaimed Planet Earth BBC television series.
John Spies in the midst of the rising white columns and falling stalactites at the Tham Lod in Pang Mapha, Thailand
Dave Pierce photographed at the entrance chamber of Tham Nam Lang in Pang Mapha, Thailand.
John Spies photographed at the entrance chamber of Tham Susa, a filming site for BBC's Planet Earth sequence in Pang Mapha, Thailand
Cave adventurer Ian Robinson is silhouetted in the dim light as he examines the Tham Pha Puak, White Cliff Cave in Pang Mapha, Thailand
Beautiful blue and green-tinged stalactites hang in the dark recesses of natural caves in Pang Mapha, Thailand
Vulcanites, the relatively rare formations of floating calcite rafts photographed in Tham Pha Mon cave in Pang Mapha, Thailand
Shan Man Ong, standing on the bamboo raft explores the downstream entrance of Tham Lod cave in Pang Mapha, Thailand
Suphaporn Singnakphum examines the decorated chamber in Tham Fossil 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
Dave Pierce examines the crisp lines of the flowstone at Tham Pha Mon cave in Pang Mapha, Thailand
Intrepid adventurer David Pierce sits back in wonder to take in the Tham Mae Lana, flowstone in the main stream passage in Pang Mapha, Thailand
It may resemble a wasps nest but this is a rock formation called a cave pendulite hanging in Tham Pha Mon cave in Pang Mapha, Thailand
Oolites or cave pearls are sedimentary rocks formed from ooids, spherical grains composed of concentric layers. These were photographed in a cave in Pang Mapha, Thailand
Kerry Hamilton climbs a cave rope attached to bamboo scaffolding to scale the inner waterfall of Tham Susa in Pang Mapha, Thailand
Ian Robinson explores the Tham Pha Puak (White Cliff) Cave in Pang Mapha, Thailand
Replies
The beauty of Mother Earth sometimes takes my breathe away - hard to find words to describe - awesome thank you ox
breathtaking.. kalki .!!!!
wonders of this gorgeous planet!!!!!!
This is beautiful ... thanks Kalki ... ;) i have a glimpse to similar beauty when i visit Israel, there are a Soreq Caves not as big as this one ... but spectacular nevertheless ... (the pictures are not mine) ...
Absolutely beautiful stuff. We have Cave of the Mounds in Wisconsin.
Oooh beautiful! Thank you!