A city skyline is the outline of a city's buildings and structures against the sky, often seen from a distance. It typically features a mix of architectural styles, including skyscrapers, historical buildings, and modern constructions. The skyline can vary greatly depending on the city's layout, geography, and urban planning. Skylines are often iconic and can represent a city's identity, such as the New York City skyline with its famous Empire State Building or the Chicago skyline known for its unique Art Deco architecture. They are popular subjects for photography and tourism, showcasing the urban landscape.