Find a place on a 1:50,000 Ordnance Survey map (can be zoomed in to street view, 1:10k, but not 1:25k Explorer maps).
This map incorporates a place/postcode search to enable us to research future rides.
For a really well written planning experience have a look at Where's the Path? which enables route planning on full screen OS maps and allows creation of GPX files.
Open Space Webmap-builder Code