Circuses are a form of entertainment that includes something for just about everyone. As a traveling unit of clowns, acrobats, animal acts and a range of other performers, the circus enjoys a history that goes back to the heyday of the Roman Empire. Generally, the focus of the performing area is referred to as a ring, owning to the circular nature of the space. Because circuses are traveling companies, tents are used for much of the live performances and housing for the animals and props, while the performers and other circus workers tend to live in trailers and wagons.