Alpine Club
The object of the Alpine Club is to promote mountain climbing and exploration throughout the world, develop a better knowledge of the mountains through literature, science and art, and through its meetings and publications, encourage protection of the mountain environment, and conserve the Club's heritage.
http://www.alpine-club.org.uk/

Brathay Exploration Group
Has run expeditions since 1947. Why not join one?
http://www.brathayexploration.org.uk/

Bukima Adventure Tours
Specializes in tailor made and group adventure tours, expeditions, overland tours to numerous destinations worldwide.
http://www.bukima.com/

Charity Challenge
Undertake an adrenaline-pumping physical challenge in any corner of the world, whilst raising vital funds for the charity of your choice.
http://www.charitychallenge.com/

Dakar.com
Official website of the world famous Paris-Dakar Rally.
http://www.dakar.com/

Dragoman
If you have between 2 and 36 weeks free, then try one of the African overland safaris offered by this tour company or travel with them across South America or Asia.
http://www.dragoman.com/

Earthwatch
Interested in joining and expedition? Earthwatch can put you in touch with scientists running projects all over the globe who could do with a helping hand.
http://www.earthwatchexpeditions.org/
http://www.earthwatch.org/expedselect.html
http://www.earthwatch.org/location/guide.html

Encounter
Encounter runs adventurous active holidays and overland expeditions throughout South America, Africa and Asia. These trips range from 2 to 26 weeks in length. They will take you there - wherever 'there' may be - and then you can choose what you want to do.
http://www.encounter-overland.com/

Everest
Covers the search for Mallory and Irvine, humans and altitude, routes to the top and the history and culture surrounding Everest.
http://www.pbs.org/wgbh/nova/everest/

Expedition Cruises
Antarctica travel specialist.
http://www.expeditioncruises.com/

Expedition Kit.co.uk
Supplier of essential kit to expeditions, organizations, the military, schools, youth groups and clubs.
http://www.expeditionkit.co.uk/

ExpeditionTrips.com
Adventure cruises in small ships to destinations such as Antarctica, Alaska and the Galapagos Islands.
http://www.expeditiontrips.com/

ExplorersWeb
Independent guides and news on mountaineering, ocean sailing, polar treks and other aspects of expedition travel.
http://explorersweb.com/

Fielding's DangerFinder
Tips and advice on planning and executing a successful expedition.
http://www.comebackalive.com/df/advcalls.htm

Geographic Expeditions
Expeditions to the ends of the Earth for committed adventure travellers.
http://www.geoex.com

Global Vision International
Specializes in volunteer abroad holidays , conservation expeditions and TEFL courses overseas.
http://www.gvi.co.uk/

Kumuka Expeditions
Choose from 150 tours, ranging from four days to 35 weeks in length, and covering 54 countries and 5 continents.
http://www.kumuka.co.uk/

Lindblad Expeditions
Set sail on nimble cruise ships and voyage to unique destinations around the globe, going places luxury liners can't.
http://www.expeditions.com/

National Audubon Society
This conservation society runs a number of nature odysseys and specialty and educational cruises.
http://www.audubon.org/

National Geographic
News, events and links for explorers and adventurers, along with a guide to choosing the right gear.
http://www.nationalgeographic.com/siteindex/index.html#adventure

National Geographic Traveler
Travel with National Geographic's own researchers, photographers, writers, and archaeologists on extraordinary journeys to the world's most intriguing places.
http://www.nationalgeographic.com/ngexpeditions/

Oceanic Society
The San Francisco based society runs international natural history journeys, participatory research expeditions and California whale watching trips.
http://www.oceanic-society.org/

One World Journeys
Aims to build the largest collection of stories on the Internet about the natural world. Contribute your own tale or watch the photo-documentaries on expeditions around the world.
http://www.oneworldjourneys.com/

Original Travel
Offers challenging expeditions that can be completed in a week.
http://www.originaltravel.co.uk/

Oz Bus
London to Sydney overland by bus, on a journey that lasts 12 weeks and takes in 20 countries.
http://www.oz-bus.com/

Pole to Pole
A British firm that arranges expedition cruises and specialist adventure and wildlife holidays to the Arctic and Antarctic regions.
http://www.pole-to-pole.co.uk/

Quark Expeditions
Arctic and Antarctic expeditions in the company of naturalists and lecturers.
http://www.quarkexpeditions.com/

Royal Geographical Society
Offers advice as well as grants and bursaries for expeditions. It also operates specialty and educational cruises.
http://www.rgs.org/

Scientific Exploration Society
A UK charity that operates a worldwide programme of scientific expeditions that focus on scientific, conservation, education and community aid projects.
http://www.ses-explore.org/

South American Explorers Online
Information and planning resource for anyone heading to South America.
http://www.samexplo.org/

Symbiosis Expedition Planning
Offers a complete holiday and expedition planning service for people looking for something beyond the normal package tour - particularly for those concerned about the impact of tourism on the developing world's highly sensitive environments and cultures.
http://www.symbiosis-travel.com/

Tangent Expeditions
British tour operator offering expeditions to Iceland, Greenland and the North Pole.
http://www.tangent-expeditions.co.uk/

The Explorers Club
Since 1904 this international, professional society has been a meeting point and unifying force for explorers and scientists worldwide. Its members are dedicated to the advancement of field research, scientific exploration and the ideal that it is vital to preserve man's instinct to explore.
http://www.explorers.org/

The Hunting Consortium Ltd
From the frozen reaches of Siberia to the deserts of Africa, The Hunting Consortium offers serious sportsmen the finest hunting adventures in the world.
http://www.huntcon.com/

The Rickshaw Run
A two week, two thousand mile trek across India in an auto-rickshaw.
http://www.rickshawrun.travel/

The Royal Scottish Geographical Society
Runs field excursions and expeditions, and offers grants for such activities.
http://www.geo.ed.ac.uk/~rsgs/menu.html

The Russia Experience
For those of you hankering for a Trans-Siberian, Russian or Mongolian adventure.
http://www.trans-siberian.co.uk

TerraQuest
According to the blurb on the website, TerraQuest offers visitors "Virtual expeditions on the World Wide Web".
http://www.terra-quest.com/

TNT Magazine.com
Features an unofficial, but detailed and freely downloadable, guide to travel on the Trans Siberian.
http://www.tntmagazine.com/travelzone/
http://www.activemag.co.uk/tntguides/

TrekForce Worldwide
A charity that promises tough, valuable and well organized conservation projects and placements in some of the oldest rainforests in the world.
http://www.trekforceworldwide.com/
http://www.trekforce.org.uk/

webExpeditions.net
Contains news, information and links relating to hundreds of expeditions around the world, both past and present.
http://www.webexpeditions.net/

Where There Be Dragons
Offers students, school groups, adults, and professional educators learning opportunities through off-the-beaten path, intimate, small group expeditions to China, Thailand, Vietnam, Laos, Cambodia, Tibet, India, Mongolia, Mexico, Guatemala and Peru.
http://www.wheretherebedragons.com/

Wikipedia
Find out more about the hippie trail, an overland route from Europe to Asia, made famous by intrepid young travellers in the 1960s and 70s.
http://en.wikipedia.org/wiki/Hippie_trail

World Challenge
Schools expedition company that offers a range of programmes geared to the education of youngsters from around the globe.
http://www.world-challenge.co.uk/

Zegrahm Expeditions
An American tour firm specializing in adventure expeditions worldwide, including submersible dive expeditions.
http://www.zeco.com/