Some birthday, I remember backflipping in city! (6)
I believe the answer is:
riyadh
'city' is the definition.
(capital of Saudi Arabia)
'some birthday i remember backflipping' is the wordplay.
'some' indicates a hidden word (some of the parts of the word are used).
'backflipping' shows that the letters should be reversed in order.
'hdayir' can be found hidden inside 'birthday i remember'.
'hdayir' in reverse letter order is 'RIYADH'.
'in' is the link.
(Other definitions for riyadh that I've seen before include "Arab capital" , "Middle Eastern capital" , "Middle Eastern venue" , "Capital city of Saudi Arabia" , "Saudi Arabian city" .)