My hometown of Rotterdam is in one of the most light-polluted regions of the world, so it never gets properly dark at night.
However, that absolutely pales in comparison to the light emitted by the greenhouses in the countryside just outside the city, where growth lamps burn to make sure the plants keep growing 24/7, as if it were high noon all day long. This shot shows the sky in the direction of these greenhouses at midnight, it looks like there's a forest fire going on. It's like that every cloudy night, and this is just a relatively small field of greenhouses.
On the plus side, the greenhouses do enable the 135th largest country in the world, to be the largest exporter of vegetables in the world (although not the largest producer). But as a nature lover, it does bug me to see the pollution!