A circus is most commonly a traveling company of performers that may include acrobats, clowns, trained animals, trapeze acts, hoopers, tightrope walkers, jugglers, unicyclists and other stunt-oriented artists. The word also describes the performance that they give, which is usually a series of acts that are choreographed to music. A circus is held in an oval or circular arena with tiered seating around its edge; in the case of traveling circuses this location is most often a large tent called the big top. Common acts include a variety of acrobatics and gymnastics including tightrope walking, aerial acts such as trapeze and cradle, and a variety of floor routines. Juggling is also a common act in circuses; the combination of juggling and gymnastics is called equilibristics and include acts like plate spinning or the rolling globe.A variety of animals have historically been used in acts. While the types of animals used vary from circus to circus, big cats, elephants, horses, birds, sea lions and domestic animals are the most common.