When Turkey's transport minister announced the launch of one of the most contested construction projects in Turkey - a third bridge over the Bosphorus - on 29 May, he said the date of the announcement had been chosen because it marked the anniversary of Istanbul's conquest by the Ottomans.

Now many fear that it might spell its final defeat.

Recep Tayyip Erdogan, Turkey's prime minister, who once said that a third bridge "would mean the murder of the city", has thrown his weight behind the 4.5bn Turkish lira (£1.6bn) project and the bridge is now predicted to open as early as 2015. But environmentalists, urban planners and many Istanbul residents are furious at the plan, arguing that it will create more traffic, increase the number of vehicles in Istanbul and spell an end to the few remaining green areas and urgently needed drinking water reservoirs that have so far resisted the urban sprawl. Then there's the lack of thorough geological research in a major earthquake zone.