At the Summer Palace in Beijing, a light-and-shadow "magic show" unfolds at sunset around the winter solstice. The setting sun illuminates all the arches of the Seventeen-Arch Bridge across Kunming Lake. This phenomenon results from the interplay between the sun's altitude and azimuth, the bridge's orientation, and the reflection on the lake's surface. From the first glimmers of golden light to the moment the arches are fully bathed in a mix of orange and red beams, the spectacle lasts about two to three hours.