A bell is a hollow vessel designed such that, when struck, it produces a sound. Usually bells are metallic, though some bells are made of other materials such as clay. The largest bell ever was called Tsar Bell, cast in the 1730s. However, it is not functional as a fire caused a large slab of it to break off.
Bells are used for a variety of purposes. In Western Europe, they were often used to announce church services. Clock towers usually had bells that would ring the hour, allowing the time to be heard throughout a city. In Eastern Europe and Russia, bells were usually used to announce important events, or to raise an alarm during an enemy attack. The practice of using church bells eventually spread to Russia as well. Bells are still used for religious and ceremonial reasons, and are often used in bands or orchestras as a musical instrument.