An eyesore is something that is largely considered to look unpleasant or ugly. Its technical usage is as an alternative perspective to the notion of landmark. Common examples include dilapidated buildings, graffiti, litter, polluted areas, and excessive commercial signage such as billboards. Some eyesores may be a matter of opinion such as controversial modern architecture (see also spite house), transmission towers or wind turbines. Natural eyesores include feces, mud and weeds. An eyesore is something that is largely considered to look unpleasant or ugly. Its technical usage is as an alternative perspective to the notion of landmark. Common examples include dilapidated buildings, graffiti, litter, polluted areas, and excessive commercial signage such as billboards. Some eyesores may be a matter of opinion such as controversial modern architecture (see also spite house), transmission towers or wind turbines. Natural eyesores include feces, mud and weeds. In the USA, the National Association of Realtors says an eyesore can shave about 10% off the value of a nearby listing. Clean-up programmes to improve or remove eyesores are often started by local bodies or even national governments. These are frequently called Operation Eyesore. High-profile international events such as the Olympic Games usually trigger such activity. Others contend that it is best to nip such problems in the bud by addressing them while they are small, since signs of neglect encourage anti-social behaviour such as vandalism and fly-tipping. This strategy is known as fixing broken windows. Whether some constructions are eyesores is a matter of opinion which may change over time. Landmarks are often called eyesores.