Where a flyer may go for a walk in London (8)
I believe the answer is:
birdcage
This clue is a double definition.
'where a flyer may go' is the first definition.
(place to keep a bird - something which flies)
'a walk in london?' is the second definition.
(I've seen this before)
'for' acts as a link.
(Other definitions for birdcage that I've seen before include "Enclosure for an avian" , "Enclosure for a budgie, say" , "Polly's home perhaps" , "arrangement of bars for singer" , "Walk in London" .)