The books all say that Sweet Cicely is widespread in the North and less common in the South, but in my experince it seems to very much prefer limestone country. I have seen it in abundance in the North Yorkshire Moors area (in the hedgerows, not on the moors themselves!) and yesterday we had a lovely day in the on/off rain in Dovedale where there was more of it than there was of Cow Parsley.
Aromatic and sweetly smelling of aniseed / liquorish its hard to mistake for anything else. The leaves can be chopped and added to salad or leaves and stems boiled. My favourite is to use it to cook with first gooseberries in place of sugar. Aparently, in the style of Comfrey Fritters, it is also sometimes cooked in France, dipped in thin batter and deep fried.