The many skyscrapers that line the financial district of London are a defining feature of the central business district. These buildings house many of the city's most prominent businesses, giving it an imposing presence on the skyline. Skyscrapers have been a part of the London skyline since the early 20th century, when they began to be used as office buildings. They quickly became a symbol of economic success and status. Now, in addition to being a prominent structure in the city, skyscrapers are also important for their function as office buildings.