Full days walk out of the city

With lockdown getting to me but no car or desire to use public transport, I really fancy taking a whole day out to just walk and walk and walk and hopefully see somewhere I haven't before.

I walk at a pretty normal/brisk pace. Does anyone have any good ideas on possible loops I could do that would take all day? I don't mean strolling to The Trout and back!

FWIW I'm starting around Donnington Bridge.