Epiphany is one of the main holidays in Christianity, which is celebrated by Russian Orthodox Church.  On this day in all regions of Russia the Orthodox believers attend Christmas Church service and with pray plunge into the ice-hole. Considering that the temperature at this time of year is often drop well below zero, so especially for this event the cross-shaped holes were cut into the thick ice covering rivers and lakes, where everyone can perform ablutions. This ritual symbolizes purification and spiritual rebirth.