Northern valley sees English youth returning (4)
I believe the answer is:
dale
'northern valley' is the definition.
(I've seen this before)
'english youth returning' is the wordplay.
'english' becomes 'e' (abbreviation).
'youth' becomes 'lad' (I've seen this before).
'returning' is a reversal indicator.
'e'+'lad'='elad'
'elad' backwards is 'DALE'.
'sees' is the link.
(Other definitions for dale that I've seen before include "Low ground" , "Open valley" , "An English valley" , "Up hill and down . . . ." , "Valley; Trollope's Bell and Lily" .)