Been debating whether to put this on or not because know someone is bound to say 'you should have known'!!
Flew from Stansted on 4th August, via Istanbul. Never flewn this way before so asked check-in staff where I would buy the entry visa. Very nice helpful lady told me ' we've made it easier for you, you will get visa in Dalaman'
Flight was late departing but made up time so got to Istanbul on time.
Transit time is very short, queues at passport control horrendous so jumped queue. Queried AGAIN where to buy visa. Was told DLM again.
Flight late, got to DLM about 1 hr late. Told Havas rep. needed a visa, no staff at visa desk. Big problem as only had 11 days on visa left.
Eventually, after being told, 'fly out again' (who's going to pay for ticket?) was told by 2 very officious policemen that I would have to go to Meis to renew visa and had to go through passport control.
I offered to wait until the next flight came in (one was due at 23:00hrs) they said couldn't.
So, moral of story is you must buy visa in Istanbul, no matter what any staff tell you, jump the queues as much as possible in Istanbul because transit time is very limited and query why no visa staff are not at the b****y airport 30 minutes before arrival of an incoming a/c.[

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p.s. apart from that it was a very enjoyable trip.