External Web Galleries:

Photo.net
Photo.net is an online community for photographers to connect and discuss photography, explore galleries, share photographs, and learn more about the art of photography. The site began in 1993 as Philip Greenspun's personal home page at MIT and has grown to become a community of more than 600,000 registered users working to help each other improve as photographers.
EO Photos
EO Photos showcases the outstanding landscape photography and nature photography of a select group of renowned professional and amateur photographers.  A good source of galleries for browsing. (Note that there does appear to be a slight formatting problem when viewing this page in Firefox.)
Gigrin Farm
Links to the web sites of a number of well known and successful Wildlife Photographers.
International Federation of Wildlife Photographers
Contest page of this international organisation, click on individual contest results down the left hand side to view some beautiful wildlife images.
Magnum
The web site of the famous Magnum agency for photojournalists.
The Photographers' Gallery
Featuring the work of well know past and present photographers with the opportunity to buy images.
PBase.com
PBase an image sharing and hosting web site which contains many galleries, frequently updated. Members could also use it as a way of making their own photographs available on the web.
Ansel Adams
Web site featuring the work of the American landscape photographer who died in 1984.
Laurie Campbell
Scottish wildlife photographer
Yann-Arthus Bertrand
The work of a photographer specialising in photographing the Earth from the ait using a balloon - fascinating images in a complex site which also includes portraiture (anthropology) and images of an environmental nature. Recommended (5 stars) in Amateur Photographer.
Joe Cornish
The web site of the landscape photographer Joe Cornish featuring work to be seen at his galleries in Northallerton and Stokesley
Steve Gosling
Web site containing galleries which feature the work of Steve Gosling a freelance photographer based in North Yorkshire, (Harrogate) who specialises in producing creative and contemporary images of the natural world - landscapes, flowers & plants, trees & foliage etc.
Charlie Waite
The web site of the English renowned landscape photographer.