Many sources of light can be seen at night. Lighthouses shine beams of light out to illuminate the coast and warn passing ships. City light illuminates a city and is made up of millions of street, office and house lights.

This picture shows a football stadium illuminated (lit up) by floodlights. Notice that floodlights need to be placed on most sides of the stadium so that there are no deep shadows which would make playing football impossible. A huge amount of power is used making floodplights almost as bright as sunlight.