There is a defining moment when the natural twilight over the land begins to dim and the lights of civilization briefly reach a balance.
The timing of that moment can not be determined in advance. It depends on the way the daylight is drawn away in cloud and sky and haze and the waking of the city lights.
One moment the city below sleeps under a golden twilight and the next it dominates the landscape.
Don't blink lest you miss it!
Photo: Robert Rath, 'A Balance of Worlds', 1/4 f/6.3 ISO100 14mm