The day of the Saint Walburga is celebrated on May 1. But the night before, April 30 or May Day Eve, is called Walpurgis Night.
Formerly the date of the pagan festival marking the beginning of summer.
According to German legend, this festival has been associated with a witches carnival, and on this night it was believed that witches met with the devil.
In these nights there were usually large bonfires in certain places in the Harz Mountains, Germany, with the purpose to dispel witches.