A team of geologists has been exploring the caves beneath the table mountains of Venezuela, where new lifeforms may have been quietly developing for millions of years. Journalist Lars Abromeit describes the expedition into the unknown.

Dark, isolated and largely unexplored, caves help astronauts prepare to do extra-terrestrial science

Cave explorer Francesco Sauro shares astonishing images from a trip into what might just be the oldest caves in the world … carved into the quartzite Tepui mountains of Venezuela.