This striking building from the time of the Austro-Hungarian Monarchy is one of the few examples for ring road architecture outside the city of Vienna. A twin building of the post office is found in the imperial spa town of Bad Ischl. Today, the post office includes an exhibition by star Swiss architect Peter Zumthor.
https://www.bregenz.travel/en/tourism/experience/tourist-attractions/architecture-in-bregenz/bregenz-post-office/