Imatrankoski rapids were formed 5000 years ago, when land rose after the Ice Age and Lake Saimaa waters tore the Salpausselkä ridge apart.
Rapids are nowadays blocked by dam, but during the summer there are daily shows, when dam is opened. The show is very popular (and free) happening gathering always hundreds of people to see magnificent nature show. Duration is about 20 min.
Rapid shows in 2020 are cancelled becauce of corona situation.