One of the first things I do when I visit a new corner of Britain, is buy a large scale map of the area, and for me, there is only one choice for the task, Ordnance Survey.
From my earliest days ferreting around on the Somerset Levels, OS Maps have held an almost reverential place of importance in my library. With them I have discovered hidden gems of woodland and water, plotted a walk or marked the spot where a badger sett, sparrowhawk nest, or countless other natural wonders have been.
The level of detail and accuracy on OS maps is unparalleled, and with a full time team of cartographers constantly surveying and updating, you can be certain that a recent edition is going to offer a thorough and comprehensive view of an area. Indeed, I take enormous pleasure in looking back at old maps of corners of the British countryside I know well, and comparing them with contemporary maps to chart the changes for the better (and occasionally worse) to our countryside.
The advent of satellite navigation has certainly added a new dimension to finding your way around, but there is nothing like, and never will be anything like, a good paper map for getting a real feel of where you are, where you were, and where you are going next.