Ordnance Survey 1:25,000 Explorer Series

OS Explorer Mapping from Ordnance Survey is very detailed and
the best selling map among outdoor enthusiasts. It is designed for
walkers, off-road cyclists and a host of other outdoor pursuits. It
includes areas regarded as access land, rights of way, field
demarcations, viewpoints, national trail paths, and selected
tourist information (such as campsites).
Available Coverage: Whole of Great
Britain
Perfect for: Walking, Climbing, Off-Road Cycling,
Topographical Site Surveys
Last updated: July 2011
Sample images
OS 1:25,000 2D (click to enlarge)