John & Anne Nuttall's website - a must for summit baggers
Alan Dawson's website - for up-to-date information about the Marilyns
The Database of British and Irish Hills - home of the DoBIH
G and J Surveys - YouTube channel by John Barnard, Graham Jackson and Myrddyn Phillips, hosting clips about some of their past, present and future surveying projects
Myrddyn Phillips interviews - Myrddyn Phillips's YouTube interviews on hill bagging and related topics, including interviews with Graham Jackson from the DoBIH survey team, and John and Anne Nuttall
Mountain Views - Hillwalking Resource for Ireland, with similar aims and features to this site
Summit Photo website - Collection of hill summit photographs, which can be viewed via thumbnail links from the mountain details pages on this website. If you would like to contribute photos to the collection, please click on the link
Ordnance Survey - Britain's national mapping agency
Streetmap - excellent source of maps in digitised format - I obtained most of my background maps for this site from here
Bing Maps - another source of digitised maps
GPS Utility - GPS Software to download - even the free unregistered version is good
Garmin - GPS equipment manufacturers
Scottish Mountaineering Club (SMC) - publisher of Munro's Tables and other Scottish hill guidebooks
Phil Newby's GPS site - waypoints in all sorts of formats, as well as lots of other GPS stuff
RHB Discussion Group - for Marilyn bagging and other hill-walking related topics
UK Walking Forum - Walking and Hiking Forum
MyOpenCountry - in depth articles on hiking and backpacking skills, guides and gear reviews
Outdoors Generations - in-depth articles, how-to guides, and product reviews on various categories of the outdoors experience
Been There - Done That - An "unofficial guide to Great Britain"
Welsh 3000s Challenge / 14 Peaks / 15 Peaks
My Pennines - walking diary, info and routes of a Pennine walker
Peak Bagging - The English Nuttalls - walking blog and routes of a Nuttall bagger
The Happy Hiker - walking routes and advice, with GPS route downloads
Hillwalkers Gallery - pictorial guide and maps of walked mountain routes
Visorando - walking routes and route planning tool
The Wasdale Web - Online guide to Lakeland's finest valley and surrounding area
Final Furths and Furthists - research on the Furths and people who have completed the Furths
The Mountains of England and Wales volumes 1 & 2 by John & Anne Nuttall - Cicerone Press, 1989 & 1990 - ISBN 1 85284 036 6 & 1 85284 037 4
The Relative Hills of Britain by Alan Dawson - Cicerone Press, 1992 - ISBN 1 85284 068 4
A Pictorial Guide to the Lakeland Fells books 1-7 by A Wainwright - Westmorland Gazette & Michael Joseph Ltd, 1955-1966
Mountain Tables by Michael Dewey - Constable & Co Ltd, 1995 - ISBN 0 09 474520 X
Complete Lakeland Fells by Bill Birkett - Harper Collins Willow, 1998 - ISBN 0583322093
The Mountain Summits of England and Wales by Chris Buxton & Gwyn Lewis - Red Dial Publications, 1986 - ISBN 0 9511723 0 1
The Mountains of England and Wales by George Bridge - Gaston's Alpine Books & West Col Productions, 1973 - now out of print