Perch by Eastern venue (4)
I believe the answer is:
site
'venue' is the definition.
(I've seen this in another clue)
'perch by eastern' is the wordplay.
'perch' becomes 'sit' (I've seen this in another clue).
'by' is a charade indicator (letters next to each other).
'eastern' becomes 'e'.
'sit'+'e'='SITE'
(Other definitions for site that I've seen before include "Spot, location" , "Location (of building, dig etc)" , "Whereabouts" , "station" , "setting" .)