Karl Ernst von Baer is one of Estonia’s most famous scientists. He’s considered to be the “father of embryology.” On the 10th anniversary of his death, a monument was erected in a park in Tartu, the city where he received his university education and spent his final years.

Every April 30, the local medical students partake in a strange ritual involving the statue. They gather at the monument and dump champagne on the man’s head. In addition to this “shower,” the students also adorn the statue with a necktie.

When exactly this tradition started is difficult to tell. From 1988 onward, the Estonian Students’ Society has led the effort.

The motivation behind this tradition is also a bit unclear. The most accepted explanation is that the champagne shower is meant to demonstrate improvements in local Estonian’s hygiene habits. Von Baer wrote his dissertation about the endemic diseases of Estonian people. One of his conclusions was that the living conditions and health habits of the lower class needed to be improved.