The longest straight line you can draw in England without crossing the sea is from Winterton on Sea in Norfolk to Pordennack Point just south of Land's End, Cornwall. It is 370 miles long.  This result surprised me because  my first attempt at drawing this line was  from  The Scottish Border north of Berwick on Tweed to the south coast at Portland Bill. That line is 367 miles and crosses Weymouth Bay for 2 1/2 miles. 

The path I have devised meanders around the initial straight line following  some simple rules:  The line taken will always be the minimum possible distance practicably walkable from the straight line.  Rivers and lakes and ponds must be crossed by bridges and streams must be fordable. Motorways and railways must be crossed by legal means. Where possible footpaths and rights of way should be taken as a preference. When  the line crosses Open Access land  as defined on recent OS maps the path assumes `rights to roam` but follows tracks visible on the ground. In the absence of footpaths, the hierarchy of choice is minor roads, roads with pavements and back streets. Walking along B roads is to be avoided where possible and A roads are avoided unless there is no other practical route. The intention is that the walk should be pleasant and interesting and get you to out of the way, obscure places, you would  never normally have an excuse or reason to visit.  It is never the intention that the route is the shortest distance. The final route as plotted is 480 miles long with a maximum elevation of 1083ft on Bodmin Moor. GPX (Global Positioning eXchange) files define the path.

All images sketched by Bob Prince 2024 ish ©