In reply to climbwhenready:
Bit of clarity: for freshwater fishing you need a rod licence from the Env Agency for anywhere (including a pond in your back garden) in England and Wales, and then permission to fish from the person how owns the fishing rights - land owner/riparian (i.e. a permit) for anywhere in UK. Close seasons exist dependent on country/ownership/coarse vs game fishing - bit complex though.
Most upland Cumbrian tarns are free fishing - some are very good for trout (and surprisingly perch in some tarns), often OK to camp as well.
Hows about North Yorkshire, through to Howgills and then Lakes? Camping/fishing tarns possibly Blea Water - Red Tarn - Codale Tarn (full of perch!) - Angle Tarn (Bowfell) or Sprinkling (Great End) .............link them together in that order, taking in highest/best summits.
If you got caught without a rod licence fishing those tarns, you would be the unluckiest fisherman ever!