Kupalo is a very old celebration that people used to have in some countries a long time ago. Imagine there was a day when people would get together and have lots of fun outside. They would sing, dance, and eat yummy food. But what made Kupalo special is that people would also do some really cool things like jumping and running over fires or even swimming in rivers and lakes!
This celebration was called Kupalo because it was named after a special flower that only blooms for a short time during the summer. People believed that this flower had magical powers that could help them stay healthy and happy. So they would pick and wear the flower as a crown during the celebration.
But Kupalo wasn't just fun and games. Some people also believed that this celebration helped to protect them from bad luck and evil spirits. They thought that by jumping over the fire or swimming in the water, they would cleanse themselves and purify their bodies and souls.
Although Kupalo is not celebrated anymore in many places, some countries still keep this tradition alive. It's a special reminder of how people used to celebrate and have fun a long time ago, and it's a way to connect with the past and keep old traditions alive.