Unfortunately, the Kupalo holiday was forgotten in Soviet times, but now we are witnessing its flourishing. The celebration is gaining popularity among young people, because in ancient times, it was on this day that the ancestors of Ukrainians traditionally looked for a mate, divined fortunes, and tried to see the future. The main actors in this national carnival were unmarried boys and girls. Who are Marena and Kupailo? Why did the children gather a lot of wildflowers that day, and what did they do with these plants? Why did the girls weave wreaths and let them float on the water? How did the boys joke on this day? Why did the party last until the morning? The apogee of the holiday was jumping over the fire, why did Ukrainians do it?