The torii typically found at Shinto shrines is a sacred gateway separating sacred from profane, and signifying that the area within is holy ground. A variety of theories exist regarding the origins of the torii, including the etymological explanation that worshipers' prayers will be "accepted" (torii-reru ) by the deity, or that it originally represented a "chicken's roost" (torii ). The original meaning of the characters used to express torii is a "bird's perch." Before the invention of clocks, the crowing of the cock was an important means of telling time.