Istanbul is the largest city in Turkey, and the most important city . It is located on the Bosphorus,
The west side is european and east side is asian,
Ankara is on asian side and actual its not a capitol city off europe, but its on the EHM tours A-110, so for the award its counts.
And politcal Turkey isn't part off europe, in 2004 started opening of accession talks between Turkey and EU.
Willem, EHM1328