It is a registered natural monument,[1] and a hole high in the trunk, reached by a ladder, functions as a dead drop or public letter box for people seeking love partners, and has a postal address.

The tree is near a forest road that branches off Bundesstraße 76 shortly after leaving Eutin in the direction of Plön, which is marked with a sign.

[3] Another custom is for a girl to walk around the tree three times under a full moon, thinking of her beloved and without speaking or laughing; she will be married within the year.

The daughter of the head forester, Ohrt, and the son of a Leipzig chocolate maker, Schütte-Felsche, were in love but her father disapproved of the relationship, so they secretly exchanged letters by leaving them in the hole in the tree's trunk.

[4][5] One man from North Rhine-Westphalia on a spa holiday in Schleswig-Holstein found a letter from a woman who lived 20 kilometres (12 mi) from him and wound up marrying her.

[2][4] On 25 April 2009 the oak itself was symbolically married to the Himmelgeist Chestnut [de], a horse-chestnut in Düsseldorf, the second tree in Germany to have a postal address.