Kupala Night (21/22 June) - Slavic Celebration of  summer solstice

Girls may float wreaths of flowers (often lit with candles) on rivers, and would attempt to gain foresight into their relationship fortunes from the flow patterns of the flowers on the river. Men may attempt to capture the wreaths, in the hope of capturing the interest of the woman who floated the wreath. (via Wikipedia)

Kupala Night is celebrated in Ukraine, Belarus, Poland and Russia currently on the night of 6/7 July. The celebration relates to the summer solstice when nights are the shortest and includes a number of Pagan rituals.

The holiday was originally Kupala - a pagan fertility rite later accepted into the Orthodox Christian calendar. Due to the popularity of the pagan celebration with time it was simply accepted and reestablished as one of the native Christian traditions intertwined with local folklore.

On Kupala day, youth jump over the flames of bonfires in a ritual testing of one’s bravery and faith.