Osteiner Hof

The Osteiner Hof is a baroque city palace at Schillerplatz in Mainz, distinguished by three rounded protrusions on its facade. Classical stone carvings ornament the windows and balcony doors throughout the structure.

Architect Johann Valentin Thomann built this palace between 1747 and 1752 for Franz Wolfgang Damian von Ostein, a member of Mainz's ruling family. After the French Revolutionary wars in 1798, it became an administrative center for the newly established department of Mont-Tonnerre.

The palace serves as the focal point for Mainz's carnival celebrations, with the official season announcement taking place from its balcony every November 11 at 11:11. This tradition makes the location a gathering point for carnival enthusiasts and remains central to the city's festive calendar.

The palace is located at Schillerplatz 1 in Mainz's old town and can be viewed from the exterior to examine German baroque architectural details. Visitors will find the best viewing perspective from the plaza side of the building.

The three rounded protrusions on the facade were an innovative design feature for its time and give the building an unusual silhouette among Mainz's other baroque structures. This distinctive detail makes it instantly recognizable on the plaza.