Horseshoes have long been regarded as a symbol of good luck. The Romans believed that the "U" shape afforded protection from evil. Some sources also state that the shape is representative of the Moon and is a fertility symbol. Its silver color was also once believed to keep away witches. The luckiest horseshoe to give to a bride comes from the near hind foot of a grey mare. To be most effective, it is said that the horseshoe should be hung by ribbons which are attached to the shoulders. A horsehoe should never be turned upside down or all the good luck of the marriage is likely to fall out.