While mentioned on a slide at Apple’s Worldwide Developers Conference, “Flyover City Tours” wasn’t explored in detail at the event. While the feature isn’t available by default in the iOS 8 betas, developer Pierre Blazquez discovered how to unlock the feature, and published a video showing the feature in action for Paris.
City Tours can best be described as a guided-camera Flyover tour. When the tour is activated, the Maps app changes to satellite mode and begins zooming and panning to different landmarks in the city, giving a helicopter tour-like effect to the view.
Currently, only the cities of Rome, Stockholm, Barcelona, New York, Paris, Glasgow, Cape Town, Perth, Bordeaux and the San Francisco Bay are available. That list will likely grow over time, with a larger list of cities enabled by time of the official debut of the feature.