the lost world

quartz arenites are the most ancient exposed sedimentary rocks on earth. a type of sandstone, they're incredibly hard, and form the basis of South America's incredible 'tepui' mountains – vast flat-topped table formations that rise above the forests and clouds of the northern Amazon. over the eons the relentless action of water has hollowed out four giant sinkholes on the Cerro Sarisariñama plateau in Venezuela. measuring more than 350m across and 300m deep, these circular voids in the forest contain their own miniature jungles – tiny worlds within worlds

read more about Cerro Sarisariñama in our latest column for AnOther