A ghost town or alternatively deserted city or abandoned city is an abandoned village, town, or city, usually one that contains substantial visible remaining buildings and infrastructure such as roads. A town often becomes a ghost town because the economic activity that supported it (usually industrial or agricultural) has failed, or due to natural or human-caused disasters such as floods, prolonged droughts, extreme heat or extreme cold, government actions, uncontrolled lawlessness, war, pollution, or nuclear disasters. The term can sometimes refer to cities, towns, and neighbourhoods that are still populated, but significantly less so than in past years; for example, those affected by high levels of unemployment and dereliction.