Which side of Charles Bridge matters, and when

Charles Bridge runs northwest–southeast across the Vltava. At sunrise, stand on the east side (Old Town Tower end) facing west toward Castle District — light comes from behind you and lands on the castle and cathedral above the water. By mid-morning it's too bright and too crowded. At sunset, light comes from the west, the castle glows, and you shoot from the east bank toward it. Letná Park, above the river on the left bank, gives the postcard panorama of the Old Town below, with a beer garden usually open until after sunset. Golden hour at 50°N runs around 50 minutes in summer, with civil twilight long enough to push the useful window to nearly 90 minutes. The Prague Old Town Clock tower has a terrace accessible by elevator on the hour — worth the queue for the compressed rooftop view.