Two of us completed this yesterday. Ullswater is perhaps not an obvious candidate for this sort of round but basically it's a traverse of the peaks on the main watershed to Ullswater.
Starting and finishing at Pooley Bridge we included Arthur's Pike, Loadpot Hill, High Street, Stoney Cove Pike, Red Screes, Dove Crag, Hart Crag, Fairfield, Dollywagon, Nethermost, Helvellyn, Raise, Stybarrow then on to Hart Side, Birkett Fell, Swineside Knott, Common Fell, Gowbarrow, Great Meldrum and not least Little Mell Fell.
I reckon the distance is about 35-40 miles with some 10,000 feet of climbing so it makes a fair day out. It's good going nearly all the way, the roughest parts coming after Birkett Fell. We took a leisurely 11-45 in a cold, strongish wind