In architecture, an atrium (plural: atria or atriums) is a large open-air or skylight covered space surrounded by a building. Atria were a common feature in Ancient Roman dwellings, providing light and ventilation to the interior. Modern atria, as developed in the late 19th and 20th centuries, are often several stories high, with a glazed roof or large windows, and often located immediately beyond a building's main entrance doors (in the lobby).
Atria are a popular design feature because they give their buildings a "feeling of space and light." The atrium has become a key feature of many buildings in recent years. Atria are popular with building users, building designers and building developers. Users like atria because they create a dynamic and stimulating interior that provides shelter from the external environment while maintaining a visual link with that environment. Designers enjoy the opportunity to create new types of spaces in buildings, and developers see atria as prestigious amenities that can increase commercial value and appeal.