Horseshoes and luck

The belief that good luck will come from hanging a horseshoe above a door
originates from beliefs related to symbols of half-circles and crescents. 

Early religions considered crescent shaped objects powerful and protective
signs. In ancient Yucatan and Peru, temples were built with arched doorways
because of this notion. In Spain the Moors designed their mosques in arch
formation. Ruins at Stonehenge, England, show that the religious grounds of the
sun-worshiping Druids were in semi-circles or horseshoe design. Down through the
Middle Ages churches and public buildings were built with arched windows and
doorways as a means of protection against evil. 

It is thought that horseshoes originated with the Greeks during the 4th Century.
Horses were held sacred at that time, so their crescent-shaped shoes became
symbols of good luck. Added power came from the fact that the horseshoes were
made from iron, the metal that people believed guarded one from the power of
witches. Until recent years, horseshoes were made to hold seven nails, a mystic
and potent number. So its no wonder that the Greeks and Romans always kept a
horseshoe nailed to the wall for protection against almost anything. 

There are two beliefs on how to hang your horseshoe. One is to hang your
horseshoe prong side up, so if the Devil should get too near, he will be sucked
in and destroyed. The other belief is that if you hang your horseshoe prong side
down, the good luck will pour out over your threshold, keeping the Devil from
crossing it.