RIVERS SHEAF AND RIVELIN/SHEFFIELD/YORKSHIRE
Sheffield City Council allows free fishing on the urban, publicly-accessible stretches of the Sheaf and Rivelin.

It's very narrow in parts with short riffles and glides of some eighteen inches deep but it has some delightfull tiny brown trout that are seemingly always willing to feed.  

You also have the Rivelin and the Loxely intertwined through the area, also, both free to fish.  Both the tributaries have smaller trout but still nothing to be sneezed at.