Traditionally, wheels were used in Tibet only for spiritual purposes; secular uses were deliberately avoided. While this is no longer the case, the beautifully embossed prayer wheels - ranging from hand-held versions to ones that are metres high and fill a whole room - are found all over Tibet and Nepal. Like prayer flags, they contain consecrated mantras, but the larger ones can hold hundreds of volumes of sacred texts. Meditating on the meaning of the mantras can lead to enlightenment, but simply reciting, or activating them by spinning the wheels, is enough to evoke the benign attention of the gods.