Looking at a little valley in geography (5)
I believe the answer is:
eying
'looking at' is the definition.
(to eye something is to look at it)
'a little valley in geography' is the wordplay.
'a little' indicates the answer is hidden within the clue (a little bit of the clue).
'EYING' is hidden within 'valley in geography'.
(Other definitions for eying that I've seen before include "Looking at closely" , "Fixated on" , "In the process of close scrutiny" , "Looking at with interest" , "Interested in visual appearance" .)