I am a huge admirer of geological maps, and recently came across this resource, which features old maps of many UK counties (scroll down to the bottom). I love how the landscape is freed from most surface details and reduced to bold colours and unusual lines. Of course, these colours, these geological structures, then inform much of life on surface (e.g. coal fields and mining towns, various rock types used in building etc). Ultimately I just like this oblique way of looking at the local environment.