Remarkable photographs, documents and maps relating to some of Britain's greatest explorers are being released by the Royal Geographical Society.
It is a £7.1m venture that will give public access to the 174-year-old RGS archives for the very first time.
Some of the materials come from the pioneering expeditions undertaken by David Livingstone, Charles Darwin, Robert Scott and Ernest Shackleton.
One item is Dr Livingstone's sketch of Victoria Falls made in 1860.
Other items on show will be the pocket sextant used by Charles Darwin on his Beagle expeditions and the oxygen tanks used on the first ascent of Everest in 1953.
The RGS, which is based in an old building in London's South Kensington, began as a "dining club" in 1827.
Its aim was the "improvement and diffusion of geographical science", and it helped to fund great expeditions, such as Shackleton's extraordinary but ill-fated Imperial Trans-Antarctic Expedition in 1914.
All the explorers - adventurers like Edmund Hillary, Thor Heyerdahl, Chris Bonington and Richard Burton - were required to return to Kensington and recount their experiences and leave behind souvenirs for the society.
The RGS also holds maps, documents and photographs offering insights into the histories of communities who migrated to the UK from the Caribbean, Africa and Asia.
For example, photographs by the explorer and colonial officer Harry Johnston are a rare photographic record of everyday life in the Caribbean after slavery in the early 20th Century.
They include photographs of the inhabitants of Nanny Town in Jamaica, a settlement of runaway slaves that resisted British rule and even negotiated autonomy for their communities in 1740.
In all there are more than two million items in the RGS archives, charting 500 years of research and exploration in what is the world's largest collection of its kind.
People wanting access to the artefacts can visit the society's new study centre opened as an extension to its building in Kensington with help from the Heritage Lottery Fund, which provided 75% of the funding.
Users can also search the heritage holdings via the internet.
Charles Darwin carried his sextant on his evolution voyages
The project is targeting schools, universities and community groups, with illustrated talks and online teaching resources as well as the chance for students to visit the centre and see historic artefacts for themselves.
Carole Souter, director of the Heritage Lottery Fund, said: "The Unlocking The Archives Project will help open up the society's treasures to a much wider audience, showing people how relevant they are to our understanding of modern day life."
Royal Geographical Society director Dr Rita Gardner said: "I believe that everyone should have the opportunity to understand the world in which they live and the impact of their lives upon it."