Life on the edge: Inside the world's largest STONE forest, where tropical rain has eroded rocks into 300ft razor-sharp spikes

Isolated and inhospitable, this huge collection of razor-sharp vertical rocks looks like the last place where wildlife would thrive.

The colossal 'Grand Tsingy' landscape in western Madagascar is the world's largest stone forest, where high spiked towers of eroded limestone tower over the greenery.

But despite its cold, dangerous appearance, the labyrinth of 300ft stones is home to a number of animal species, including 11 types of lemur.

 
Head for heights: White-legged lemurs cling to the top of a sharp limestone peak in the 'Grand Tsingy' stone forest in Madagascar
 

 
Between a rock and a high place: The white-legged lemurs are among 11 species of lemur to be found in the stone forest of the Tsingy de Bemaraha national park
 

 
Perilous: An explorer climbs among the razor-sharp peaks of the stone forest, where the eroded limestone rocks extend for 230-square miles

 
Inhospitable: The Grand Tsingy may look uninhabitable, but there are thought to be 11 species of lemur, 100 types of bird and 45 kinds of reptile living there

Its name, 'Tsingy' translates as 'where one cannot walk', due to the hazardous formations of razor-sharp pinnacles made from limestone which have been eroded by tropical rain.

Explorer and photographer Stephen Alvarez captured the beauty of the Grand Tsingy when he went there as part of an expedition for National Geographic.

As well as the dramatic backdrop of the 230-square mile limestone landscape, he also photographed lemurs leaping from rock to rock as part of their natural home in the Tsingy de Bemaraha national park.

Stephen, 47, said: 'There's forest within those rocks and animals including families of lemurs live within it.

 
Intrepid: Climbers scale another dangerous-looking peak in the Grand Tsingy, thought to be the world's largest stone forest
 

 
Our home: A Deckens Sifaka peers out from behind a sharp rock within the stone forest

 
Hanging loose: Lemurs in the Grand Tsingy stone forest are often spotted leaping from rock to rock, having made themselves at home in the dangerous environment

 
On the edge: A Deckens Sifaka clings to a single razor-sharp shard of limestone within the enormous 600-square km forest

'It's an unbelievable experience to watch them, they forage in the forest in the day and jump like acrobats from the sharp pinnacles where they sit at night.

I'd never seen a landscape like it. 'My first impression was thank god, it was more tremendous than I had ever imagined and I knew straight away I would be able to get some fantastic photos.

Stephen said the Tsingy was so remote it took him five days to reach it from Madagascar 's capital and it was so difficult to explore it took a whole day to walk just half a mile.

 
Flying solo: A lemur leaps through the air from one rock to another, making light of its hazardous surroundings in Madagascar
 

 
Forest of life: Various forms of greenery can be spotted within the Grand Tsingy stone forest, despite the apparently inhospitable environmental conditions

 

 
Cavernous: The Grand Tsingy is a test for even the most intrepid explorer or climber, but is still a home to many forms of natural life

'It's like a cave without a roof, it gets a tremendous amount of tropical rain that has eroded the rock into these sharp rock pinnacles.

'The rocks themselves are really sharp, they stick up like giant steak knives. It is one of the most difficult places I've ever explored.'

As well as lemurs, the Tsingy de Bemaraha national park is also home to the small carnivorous falanouc, the ring-tailed mongoose, and several bats.

More than 100 species of bird have also been recorded as living in the park, along