Complex sentence: In places very close to the poles this is true, but in areas very close to the Arctic and Antarctic Circles, midnight sun is experienced, but they experience polar twilight instead of the polar night.
Split into simpler sentences: In places very close to the poles this is true, but in regions that are located at the inner border of the polar circles where midnight sun is experienced, this is not true. Due to twilight, these regions experience polar twilight instead of the polar night.