The tiny tropical island of Ascension is not easy to find. It is incredibly remote, located 1,600km (1,000 miles) from the coast of Africa and 2,250km (1,400 miles) from South America.
Its existence depends entirely on what geologists call the mid-Atlantic ridge. This is a chain of underwater volcanoes formed as the ocean is wrenched apart.
However, because Ascension occupies a "hot spot" on the ridge, its volcano is especially active. A million years ago, molten magma explosively burst above the waves.
A new island was born.
Back in 1836, the young Charles Darwin was coming to the end of his five-year mission to explore strange new worlds and boldly go where no naturalist had gone before.
Aboard HMS Beagle, he called in at Ascension. En route from another remote volcanic island, St Helena, Darwin wasn't expecting much.
"We know we live on a rock, but the poor people of Ascension live on a cinder," the residents of St Helena had joked before his departure.
But arriving on Ascension put an unexpected spring in Darwin's step.
Professor David Catling of the University of Washington, Seattle, is retracing Darwin's travels for a new book. He told the BBC: "Awaiting Darwin on Ascension was a letter from his Cambridge mentor, John Henslow.
"Darwin's voyage of discovery had already caused a huge sensation in London," he explained.
"Henslow assured him that on his return, he would take his place among the great men of science."
At this fantastic news, Darwin bounded forth in ecstasy, the sound of his geological hammer ringing from hill to hill.
Everywhere, bright red volcanic cones and rugged black lava signalled the violent forces that had wrought the island.
Yet, thinks Professor Catling, amid this wild desolation, Darwin began to hatch a plot.
Out of the ashes of the volcano, he would create a green oasis - a "Little England".
Read More @ BBC
