Photographer Robbie Shone goes deep underground with the Hong Meigui Expedition in China.
Climbing the rope up a vertical section of cave known as a pit in Xinu Attic.
American cave explorer Mike Ficco places bolts and begins his descent of a vertical pit in a cave called Xinu Attic.
Expedition members Mike Ficco and Erin Lynch carry bags of equipment back from the cave late in the evening.
The view back towards the towering entrance and the main river passage in Quankou Dong. Thick beds of limestone break through towards the ceiling high up above the floor of the cave.
Typical kitchen scene inside the rural farmhouse whilst a meal is being prepared up at the remote village of Ranjiagou. The fire is kept alight below the large circular stove.
Blind Fish without any eyes swim around in small pools of water in Qi Dong.
Two cave explorers are dwarfed for scale in a section of cave called Dancing Elephant Troop. Here two huge passages intercept and form a giant section of empty space, deep underground in San Wang Dong.
Hong Meigui team members, Duncan Collis and Matt Ryan make progress along an awkward stretch of passage known as "Where the Wind Blows" underground in San Wang Dong, suitably named because of the strong wind that whistles through this small tunnel, churning up dust and sand particles into the air.
Perfectly situated in the middle of the passage, this giant calcite stal boss makes a huge statement. Dwarfed by it's sheer size, Hong Meigui team member, Matt Ryan can only look up in amazement. This is one of many gigantic formations in San Wang Dong.
Gaining height step by step, Duncan Collis climbs a thin rope up to a small ledge overlooking the vast floor surface of Niubizi Tian Keng in the Er Wang Dong cave system.
The underground camp in Sang Wang Dong is a cosy and warm place to stay. Hot food and drink recharge weary and tired explorers before taking a few hours sleep in either suspended hammocks or on roll mats on the floor.
Deep pools of water challenge cave explorers Erin Lynch and Lars Abromeit as they try to remain dry through the awkward sections of Queen of the Nile, deep underground in San Wang Dong.
Hong Meigui co-founder Erin Lynch prepares to descend down into the black chasm below her. A deafening waterfall plummets behind, whipping up wind and spray into the air. This is the entrance to a section of cave called Queen of the Nile.
Large stalagmites at the foot of a giant ramp to another level of caves in San Wang Dong create a spectacle midway in a section of cave called Crusty Duvets. The jagged, uneven floor surrounding the three formations is as delicate and untouched as the stalagmites themselves.
American speleologist Erin Lynch struggles to pull her way across a raging torrent of white water that could tear her away from her only lifeline, sending her on a treacherous path down the main river in Quankou Dong.
Suspended on a thin rope a tiny figure is dwarfed by the sheer size on a monumental scale of Cloud Ladder Hall. The beam of light cast by anothers headtorch pierces the fog yet illuminates nothing. This naturally formed room is so large it has it's own weather system going on.