The bay of Beykoz is the Bosphorus at its widest. The village of Beykoz is the last substantial village on the Asian shore – in fact it is huge, several towns, almost countries rolled into one. Arrive by sea and you step into a hard-working gritty affair, an old-fashioned village little changed since the scruffy seventies. Enter Beykoz from the Fatih Bridge and you might be descending to Lugano. Freeways and viaducts fly through the hills past smart housing estates and forest ending in a narrow avenue of century-old planes. Who will win the day?