Osterfeuer

Easter fires are typically bonfires lit at Easter as part of liturgical and secular celebrations.

Fire can feature prominently during solemn Easter Vigil celebrations held after sunset on Holy Saturday, concluding the Paschal Triduum. Such a fire might be used to light a Paschal candle or other candles used symbolically before or during mass or other religious celebration.

As a sacrament in remembrance of the Resurrection of Jesus, the Catholic mass according to Roman rite begins with a celebration of light (Lucernarium): an open fire is lighted ouside the church and blessed by the priest; when the Paschal candle is lit, the community ceremoniously enters the dark church chanting Lumen Christi and Deo gratias. The present-day rite normally follows the 1955 liturgical reforms of Pope Pius XII and the Summorum Pontificum of 2007. While the Old Catholic rite deviates only in a few points, traditional Protestant (Lutheran) celebrations excluded fire blessings. According to the Eastern Orthodox tradition of the Holy Fire, worshippers light candles from the Paschal trikirion during service at Saturday Midnight, while the troparion is sung.

On Holy Saturday or Easter Sunday, in rare occasions also on Easter Monday, large fires are lit at dusk in numerous sections of Northwestern Europe. These regions include Denmark, parts of Sweden as well as in Finland, Northern Germany, Switzerland, and Austria.

...
Wikipedia