Seville arguably holds the most elaborate processions for Holy Week anywhere in the world. A tradition that dates from medieval times is notable for featuring the procession of pasos, lifelike wood sculptures of individual scenes of the events that happened between Jesus' arrest and his burial, or images of the Virgin Mary showing grief for the torture and killing of her son. These pasos are physically carried in the shoulders of costaleros (literally sack men, usually bodybuilder types who are used to carrying extreme weights). The pasos are set up and maintained by hermandades and cofradías, religious brotherhoods, confraternities or sodalities, whose precede the paso dressed in Roman military costumes or penitential robes. Those members who wish to do so wear these penitential robes with conical hats, or capirotes, used to conceal the face of the wearer. The robes were widely used in the medieval period for penitents, who could demonstrate their penance while still masking their identity. (These robes intentionally served as the basis for the traditional uniform for members of the Ku Klux Klan in the United States, ironically a very anti-Catholic organisation.) These Nazarenos carry processional candles or wooden crosses, may walk the city streets barefoot, and may carry shackles and chains in their feet as penance. A brass band may accompany the group, playing funereal religious hymns or marchas written for the occasion.